All The Claims

1. A data distribution system including an information service center and terminal equipment remote from the information service center and adapted for distributing a program selected at the terminal equipment from the information service center to the terminal equipment, the information service center comprising:
storage means for storing a plurality of programs;
retrieving means for retrieving a desired program selected at the terminal equipment from the plurality of programs stored in the storage means;
dividing means for dividing the desired program retrieved by the retrieving means into an outline part for informing a user of an outline of the desired program and into a supplement part recombinable with the outline part for restoring the desired program, wherein the outline part is of a lower quality than the desired program; and
transmission means for transmitting the outline part first followed by the supplement part to the terminal equipment; and
the terminal equipment comprising:
receiving means for receiving the outline part first followed by the supplement part of the desired program transmitted from the information service center;
a storage device;
recombining means for recombining the outline part and the supplement part to restore the desired program while the supplement part is being received by the receiving means after the reception of the outline part is completed and for storing the restored program in the storage device while the supplement part is being received; and
reproducing means for reproducing the lower quality outline part while the lower quality outline part is being received and for continuing the reproduction of the lower quality outline part while the supplement part is being received until the reproduction of the lower quality outline part is completed, thereby monitoring the desired program while the recombining means restores the desired program.
2. The data distribution system as set forth in claim 1, wherein the desired program includes audio data; and the dividing means comprises:
audio data dividing means for dividing the audio data into a plurality of bands having different respective frequency components; and
encoding means for encoding a frequency component of each of the bands resulting from a division of the audio data by the audio data dividing means by allocating a quantization bit to each one of the frequency components for masking a quantum noise, for providing as the outline part an output corresponding to a first band of the plurality of bands, and for providing as the supplement part an output corresponding to a second band of the plurality of bands.
3. The data distribution system as set forth in claim 1, wherein:
the desired program includes audio data; and
the dividing means generates a first output through addition of a plurality of channels for the audio data and a second output through subtraction of the plurality of channels, for providing one of the first output and the second output as the outline part and a remaining output as the supplement part.
4. The data distribution system as set forth in claim 1, wherein:
the desired program includes audio data; and
the dividing means comprises frequency component dividing means for dividing frequency components of the audio data into an even spectrum and an odd spectrum for providing one of the even spectrum and the odd spectrum as the outline part and an other spectrum as the supplement part.
5. The data distribution system as set forth in claim 1, wherein:
the desired program includes audio data; and
the data dividing means divides the audio data into vocal data and accompaniment data for providing one of the vocal data and the accompaniment data as the outline part remaining data as the supplement part.
6. The data distribution system as set forth in claim 1, wherein, when the supplement part from the information service center begins downloading into the terminal equipment, the outline part is continuously reproduced for monitoring by the user.
7. The data distribution system as set forth in claim 1, wherein reproduction of the outline part at the terminal equipment for monitoring is not counted for billing.
8. The data distribution system as set forth in claim 1, wherein the information service center transmits to the terminal equipment the supplement part including additional lock data for a predetermined billing and receives from the terminal equipment key data corresponding to the additional lock data, thereby permitting reproduction of the supplement part at the terminal equipment.
9. A method of distributing a program between an information service center and terminal equipment remote from the information service center, comprising the steps of:
dividing a desired program selected at the terminal equipment into an outline part for informing a user of an outline of the desired program and into a supplement part recombinable with the outline part for restoring the desired program, wherein the outline part is of a lower-quality than the desired program;
transmitting the outline part first followed by the supplement part to the terminal equipment;
receiving at the terminal equipment the outline part first followed by the supplement part of the desired program distributed from the information service center;
recombining the outline part and the supplement part to restore the desired program while the supplement part is being received after the reception of the outline part is completed;
storing the restored program while the supplement part is being received; and
reproducing the lower quality outline part while the lower quality outline part is being received and for continuing the reproduction of the lower quality outline part while the supplement part is being received until the reproduction of the lower quality outline part is completed, thereby monitoring the desired program while the desired program is being restored.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1. A mounting system for supporting tooling comprising a base block having a first block surface and a second block surface, the first block surface being configured to support an associated object such as tooling or additional tooling blocks, the base block further including a plunger passage and a stud passage, the plunger passage extending into the base block from the second block surface and extending inwardly along a plunger passage axis, the stud passage extending into the base block from the first block surface along a stud passage axis and the stud passage axis being generally transverse to the plunger passage axis and radially spaced from the plunger passage axis, the stud passage partially intersecting the plunger passage forming a locking region between the plunger passage axis and stud passage axis, the system further including a plunger extending along a plunger body axis between an inner plunger end and an outer plunger end, the plunger including an outer side surface between the inner and outer plunger ends that extends about the plunger body axis, the plunger passage being shaped to receive the plunger in a sliding relationship and allowing the plunger to slide axially in the plunger passage along the passage axis, the plunger being axially positionable in the passage between an unlocked position and a locked position that are axially spaced from one another along the passage axis, the plunger having a radial cam region between the plunger ends facing radially outwardly from the plunger body axis, the radial cam region including an axially extending locking plunger cam and a clearance path axially adjacent the plunger cam along the plunger body axis, the stud passage being shaped to receive an associated stud, the associated stud extending between a stud inner end and a stud outer end along a stud body axis, the associated stud having a stud cam between the stud ends transverse to the study body axis, the stud cam being shaped to engage the plunger cam, when the plunger is in the unlocked condition the clearance path of the cam region is aligned with the stud passage allowing the stud cam of the associated stud to enter the locking region of the base block, once the stud cam is positioned in the locking region axial movement of the plunger along the plunger axis toward the locked position urging the plunger cam into the associated stud cam and the plunger cam at least partially axially aligning the associated stud in the stud passage, the engagement force between the plunger and stud cams urging the associated stud into a locked condition thereby locking the associated stud relative to the base block and providing a hold-down force between the base block and the associated stud.
2. A mounting system according to claim 1, wherein the plunger includes a plunger thread and the base block including a block thread threadingly engagable with the plunger thread to produce the axial movement of the plunger.
3. A mounting system according to claim 1, wherein the plunger further includes a plunger body and a plunger sleeve, the plunger sleeve being rotatable about the plunger axis relative to the plunger body, the plunger sleeve including the plunger cam and the plunger body including the plunger thread.
4. A mounting system according to claim 1, wherein the plunger further includes a plunger body and a plunger sleeve, the plunger sleeve being rotatable about the plunger axis relative to the plunger body, the plunger sleeve including the plunger cam.
5. A mounting system according to claim 4, wherein the base block further includes a plunger retainer extending to the plunger passage, the plunger retainer at least partially controlling alignment of the plunger cam
6. A mounting system according to claim 4, wherein the plunger retainer controls at least one of axial travel of the plunger in the plunger passage and rotation of the plunger in the plunger passage
7. A mounting system according to claim 1, wherein the stud passage extends downwardly from the block top.
8. A mounting system according to claim 1, wherein the stud passage is a first stud passage and the locking region is a first locking region, the base block further including a second stud passage spaced axially from the first stud passage along the plunger axis forming a second locking region, the radial cam region is a first cam region with a first plunger cam and an axially spaced first clearance path, the plunger further including a second radial cam region with a second plunger cam and an axially spaced second clearance path for the second cam region
9. A mounting system according to claim 8, further including a first stud and a second stud, the first stud being configured to enter the first stud passage and the second stud being configured to enter the second stud passage, each of the first and second studs including a stud inner end and a stud outer end along a stud axis, the each stud having a locking stud cam between the stud ends and transverse to the stud axis, when in the unlocked condition the corresponding clearance path of the plunger being aligned with the first and second stud passages allowing the stud cam of the each stud to enter the corresponding locking region, once the each stud is in the locking region axial movement of the plunger along the plunger axis directing the corresponding pull plunger cams into the corresponding stud cams thereby engaging the plunger cams against the stud cams.
10. A mounting system according to claim 9, wherein at least one of the first and second studs includes a locating ring having a radially outward surface machined to a desired tolerance, at least one of the stud passages including a locating hole portion having an inward surface machined to a desired tolerance, the inward surface and outer surface being dimensioned to produce a close tolerance fit between the at least one stud and the at least one stud passage for at least in part locating the stud relative to the base plate.
11. A mounting system according to claim 1, further including a stud and the stud being joined to an associated top tooling, the stud extending between a stud inner end and a stud outer end along a stud axis, the stud having a locking stud cam between the stud ends and transverse to the stud axis, when in the unlocked condition the clearance path of the plunger is aligned with the stud passage allowing the stud cam to enter the locking region, once the stud is in the locking region axial movement of the plunger along the plunger axis directing the plunger cam into the stud cam thereby engaging the plunger cam against the stud cam and urging the stud into the stud passage and providing a hold-down force between the base block and the stud.
12. A mounting system according to claim 11, wherein the stud includes a locating ring having a radially outward surface machined to a desired tolerance, the stud passage including a locating hole portion having an inward surface machined to a desired tolerance, the inward surface and outer surface being dimensioned to produce a close tolerance fit between the stud and the stud passage for at least in part locating the stud relative to the base plate.
13. A mounting system according to claim 1, wherein the associated devices is an associated workholding device including at least one of a fixturing plate, a dumb bell riser and a vise.
14. A mounting system according to claim 1, wherein the system includes a plurality of plungers and a plurality of studs, at least one of the plurality of stud including a locating stud wherein at least a portion of the at least one stud has a close tolerance fit with the stud passage to locate the associated device relative to the base block.
15. A mounting system according to claim 1, wherein the plurality of studs is greater than the plurality of plungers.
16. A mounting system according to claim 1, wherein the stud passage is a first stud passage and the base block further including a second and a third stud passage space axially from the first stud passage along the plunger axis forming a second and a third locking region respectively, the radially extending plunger cam region is a first cam region with a first plunger cam and an axially spaced first clearance path, the plunger further including a second and a third cam region with a second and third plunger cams and axially spaced second and third clearance path for the second and third cam region respectively, the system including three studs.
17. A mounting system according to claim 1, wherein the plunger passage is a blind hole.
18. A mounting system according to claim 1, wherein the plunger is inset within the plunger passage when in the locked condition.
19. A mounting system according to claim 1, further including a mounting arrangement to secure the base block to another workholding element.
20. A mounting system according to claim 19, wherein the mounting arrangement includes openings in the base block and at least one of threaded screws and locating pins.
21. A mounting system for supporting tooling comprising a base block and at least one locking stud, the base block having a first block surface and a second block surface, the first block surface being configured to support an associated object such as tooling or additional tooling blocks, the at least one locking studs being attachable to the associated object such that the at least one studs are fixed relative to the associate object, the base block further including a plunger passage and a stud passage, the plunger passage extending into the base block from the second block surface and extending inwardly along a plunger passage axis, the stud passage extending into the base block from the first block surface along a stud passage axis and the stud passage axis being generally transverse to the plunger passage axis and radially spaced from the plunger passage axis, the stud passage partially intersecting the plunger passage forming a locking region between the plunger passage axis and stud passage axis, the system further including a plunger extending along a plunger body axis between an inner plunger end and an outer plunger end, the plunger including an outer side surface between the inner and outer plunger ends that extends about the plunger body axis, the plunger passage being shaped to receive the plunger in a sliding relationship and allowing the plunger to slide axially in the plunger passage along the passage axis, the plunger being axially positionable in the passage between an unlocked position and a locked position that are axially spaced from one another along the passage axis, the plunger having a radial cam region between the plunger ends facing radially outwardly from the plunger body axis, the radial cam region including an axially extending locking plunger cam and a clearance path axially adjacent the plunger cam along the plunger body axis, the stud passage being shaped to receive one of the at least one studs, the at least one stud extending between a stud inner end and a stud outer end along a stud body axis, the at least one stud having a stud cam between the stud ends transverse to the study body axis, the stud cam being shaped to engage the plunger cam, when the plunger is in the unlocked condition the clearance path of the cam region is aligned with the stud passage allowing the stud cam of the at least one stud to enter the locking region of the base block, once the stud cam is positioned in the locking region axial movement of the plunger along the plunger axis toward the locked position urging the plunger cam into the stud cam and the plunger cam at least partially axially aligning the stud in the at least one stud passage, the engagement force between the plunger and stud cams urging the at least one stud into a locked condition thereby locking the at least one stud relative to the base block and providing a hold-down force between the base block and the at least one stud.
22. A mounting system according to claim 21, wherein the plunger further includes a plunger body and a plunger sleeve, the plunger sleeve being rotatable about the plunger axis relative to the plunger body, the plunger sleeve including the plunger cam and the plunger body including a plunger thread,
23. A mounting system according to claim 21, wherein the base block further includes a plunger retainer extending to the plunger passage, the plunger retainer at least partially controlling alignment of the plunger cam.
24. A mounting system according to claim 23, wherein the plunger retainer controls at least one of axial travel of the plunger in the plunger passage and rotation of the plunger in the plunger passage.
25. A mounting system according to claim 21, wherein the stud passage is a first stud passage and the locking region is a first locking region, the base block further including a second stud passage spaced axially from the first stud passage along the plunger axis forming a second locking region, the radial cam region is a first cam region with a first plunger cam and an axially spaced first clearance path, the plunger further including a second radial cam region with a second plunger cam and an axially spaced second clearance path for the second cam region, the mounting system including at least to studs.
26. A mounting system according to claim 9, wherein the system includes a plurality of studs and at least one of the plurality of studs including a locating ring having a radially outward surface machined to a desired tolerance, at least one of the stud passages including a locating hole portion having an inward surface machined to a desired tolerance, the inward surface and outer surface being dimensioned to produce a close tolerance fit between the at least one stud and the at least one stud passage for at least in part locating the stud relative to the base plate.
27. A mounting system according to claim 21, wherein the stud is joined to at least one of a fixturing plate, a dumb bell riser and a vise.
28. A mounting system according to claim 21, wherein the hold down stud is part of a dumb bell.
29. A mounting system according to claim 1, wherein the stud cam extends about the stud.
30. A mounting system according to claim 1, wherein the stud cam is an axial pocket and at least in partially locates the stud rotationally about the stud axis.
31. A mounting system according to claim 1, wherein the stud is shaped to be received in the stud passage in a predetermined rotational position.

1. A memory device comprising:
a memory array;
a temporary storage area; and
circuitry operative to:
store, in the temporary storage area: (i) first data to be stored in row N in the memory array, (ii) second data, if any, stored in row N\u22121 in the memory array, and (iii) third data, if any, stored in row N+1 in the memory array;
write the first data in row N in the memory array; and
in response to an error in writing the first data in row N in the memory array:
write the first data, the second data, if any, and the third data, if any, in respective rows in a repair area in the memory device; and
add addresses of rows N\u22121, N, and N+1 to a table stored in the memory device, wherein the table indicates which rows in the repair area should be used instead of rows N\u22121, N, and N+1.
2. The memory device of claim 1, wherein the circuitry is operative to write the first data, the second data, if any, and the third data, if any, in respective rows in the repair area such that there are intervening blank rows between the respective rows.
3. The memory device of claim 1, wherein the circuitry operative to add the addresses of rows N\u22121, N, and N+1 to the table such that there are intervening blank rows between the addresses in the table.
4. The memory device of claim 1, wherein the circuitry is further operative to:
receive a command to perform one of a read or a write operation to an address of one of rows N\u22121, N, and N+1;
compare the address to addresses listed in the table; and
determine which address in the repair area should be used for said one of a read or a write operation instead of the address of said one of rows N\u22121, N, and N+1.
5. The memory device of claim 1, wherein third data is not stored in row N+1 in the memory array, and wherein the circuitry is further operative to:
store, in the temporary storage area of the memory device, third data to be stored in row N+1 in the memory array; and
in response to the error in writing the first data in row N in the memory array, write the third data in a row in the repair area in the memory device.
6. The memory device of claim 1, wherein a row stores two pages of data, wherein the first data comprises a first page of data, wherein row N stores a second page of data, and wherein the circuitry is further operative to:
store, in the temporary storage area, the second page of data; and
in response to the error in writing the first data in row N in the memory array, write the second page of data in a same repair row in the repair area as the first data.
7. The memory device of claim 1 further comprising a controller in communication with the memory array, wherein the temporary storage area and the circuitry are part of the controller.
8. The memory device of claim 1, wherein the memory array comprises a three-dimensional memory array comprising a plurality of memory cell layers stacked vertically above one another above a single silicon substrate.
9. A memory device comprising:
a memory array;
a temporary storage area; and
circuitry operative to:
receive an address of row N in the memory array;
determine whether the address of row N is present in a table stored in the memory device;
if the address of row N is present in the table, remap the address to an address in a repair area of the memory device;
if the address of row N is not present in the table:
store, in the temporary storage area: (i) first data to be stored in row N in the memory array (ii) second data, if any, stored in row N\u22121 in the memory array, and (iii) third data, if any, stored in row N+1 in the memory array;
write the first data in row N in the memory array; and
in response to an error in writing the first data in row N in the memory array:
write the first data, the second data, if any, and the third data, if any, in respective rows in a repair area in the memory device; and
add addresses of rows N\u22121, N, and N+1 to the table,

wherein the table indicates which rows in the repair area should be used instead of rows N\u22121, N, and N+1.
10. The memory device of claim 9, wherein the circuitry is operative to write the first data, the second data, if any, and the third data, if any, in respective rows in the repair area such that there are intervening blank rows between the respective rows.
11. The memory device of claim 9, wherein the circuitry is operative to add the addresses of rows N\u22121, N, and N+1 to the table such that there are intervening blank rows between the addresses in the table.
12. The memory device of claim 9, wherein the circuitry is further operative to remap the address of the repair area to a new address in the repair area if the address of the repair area is also present in the table.
13. The memory device of claim 9, wherein the circuitry is further operative to add an address of the row of the repair area to the table and write the data of the row to another row in the repair area if there is an error in writing the data of the row to the repair area.
14. The memory device of claim 9, wherein the circuitry is further operative to:
receive a command to perform one of a read or a write operation to an address of one of rows N\u22121, N, and N+1;
compare the address to addresses listed in the table; and
determine which address in the repair area should be used for said one of a read or a write operation instead of the address of said one of rows N\u22121, N, and N+1.
15. The memory device of claim 9, wherein third data is not stored in row N+1 in the memory array, and wherein the circuitry is further operative to:
store, in the temporary storage area of the memory device, third data to be stored in row N+1 in the memory array; and
in response to the error in writing the first data in row N in the memory array, write the third data in a row in the repair area in the memory device.
16. The memory device of claim 9, wherein a row stores two pages of data, wherein the first data comprises a first page of data, wherein row N stores a second page of data, and wherein the circuitry is further operative to:
store, in the temporary storage area, the second page of data; and
in response to the error in writing the first data in row N in the memory array, write the second page of data in a same repair row in the repair area as the first data.
17. The memory device of claim 9 further comprising a controller in communication with the memory array, wherein the temporary storage area and the circuitry are part of the controller.
18. The memory device of claim 9, wherein the memory array comprises a three-dimensional memory array comprising a plurality of memory cell layers stacked vertically above one another above a single silicon substrate.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1. A system for recovering carbon dioxide in an exhaust gas, comprising:
an absorption device which is provided with an exhaust gas introduction port, an alkaline solution introduction port, a remaining exhaust gas discharge port and an alkaline solution discharge port and causes gas-liquid contact between an exhaust gas introduced from the exhaust gas introduction port and an alkaline solution introduced from the alkaline solution introduction port to absorb carbon dioxide contained in the exhaust gas by the alkaline solution;
a regeneration device which is provided with an alkaline solution spurt port, a regenerated alkaline solution discharge port and a carbon dioxide discharge port and discharges carbon dioxide from the alkaline solution having absorbed the carbon dioxide to regenerate the alkaline solution;
a first alkaline solution reflux line which refluxes the alkaline solution being discharged from the alkaline solution discharge port of the absorption device to the alkaline solution introduction port;
a second alkaline solution reflux line which refluxes the regenerated alkaline solution being discharged from the regenerated alkaline solution discharge port of the regeneration device to the alkaline solution spurt port; and
a storage tank which is comprised of a plurality of split tanks capable of intervening in either the first alkaline solution reflux line or the second alkaline solution reflux line by switching the alkaline solution reflux lines.
2. The system for recovering carbon dioxide in an exhaust gas according to claim 1, wherein a main solute of the alkaline solution is sodium carbonate, potassium carbonate or amine.
3. A method for recovering carbon dioxide in an exhaust gas, comprising:
a first absorption step which refluxes a first alkaline solution being discharged from an alkaline solution discharge port of an absorption device to an alkaline solution introduction port of the absorption device through a first split tank among a plurality of split tanks configuring a storage tank to cause gas-liquid contact between the exhaust gas and the first alkaline solution to repeatedly absorb carbon dioxide contained in the exhaust gas by the first alkaline solution; and
a first regeneration step which switches a reflux line of the first alkaline solution to introduce the first alkaline solution having absorbed the carbon dioxide in the first absorption step to an alkaline solution spurt port of a regeneration device, refluxes the first alkaline solution being discharged from a regenerated alkaline solution discharge port of the regeneration device to the alkaline solution spurt port through the first split tank, and discharges repeatedly the carbon dioxide into the regeneration device to regenerate the carbon dioxide absorption capacity of the first alkaline solution.
4. The method for recovering carbon dioxide in an exhaust gas according to claim 3, further comprising:
a second absorption step which guides a second alkaline solution stored in a second split tank of the storage tank to the alkaline solution introduction port of the absorption device when the first regeneration step is being performed, refluxes the second alkaline solution being discharged from the alkaline solution discharge port of the absorption device to the alkaline solution introduction port through the second split tank and causes gas-liquid contact between the exhaust gas and the second alkaline solution to repeatedly absorb the carbon dioxide contained in the exhaust gas by the second alkaline solution.
5. The method for recovering carbon dioxide in an exhaust gas according to claim 4, further comprising:
a second regeneration step which switches the reflux line of the alkaline solution to introduce the second alkaline solution having absorbed the carbon dioxide in the second absorption step to the alkaline solution spurt port of the regeneration device, refluxes the second alkaline solution being discharged from the regenerated alkaline solution discharge port of the regeneration device to the alkaline solution spurt port through the second split tank, and discharges repeatedly the carbon dioxide into the regeneration device to regenerate the carbon dioxide absorption capacity of the second alkaline solution; and
a third absorption step which switches a reflux line at the same time when the reflux line is switched in the second regeneration step, guides the first alkaline solution regenerated in the first regeneration step to the alkaline solution introduction port of the absorption device, refluxes the first alkaline solution being discharged from the alkaline solution discharge port of the absorption device to the alkaline solution introduction port through the first split tank, and causes gas-liquid contact between the exhaust gas and the first alkaline solution to repeatedly absorb the carbon dioxide contained in the exhaust gas by the first alkaline solution.
6. A system for recovering carbon dioxide in an exhaust gas, comprising:
an absorption device which is provided with an exhaust gas introduction port, an alkaline solution introduction port, a remaining exhaust gas discharge port and an alkaline solution discharge port, and causes gas-liquid contact between the introduced exhaust gas and an alkaline solution to absorb carbon dioxide contained in the exhaust gas by the alkaline solution to produce a reaction product insoluble compound;
an alkaline solution reflux line which refluxes the alkaline solution being discharged from the alkaline solution discharge port of the absorption device to the alkaline solution introduction port; and
a collection tank which is intervened in the alkaline solution reflux line or connected by a pipe branched from the alkaline solution reflux line to collect an insoluble compound contained in the alkaline solution.
7. The system for recovering carbon dioxide in an exhaust gas according to claim 6, wherein the alkaline solution is produced by dissolving sodium carbonate into water, and the sodium carbonate dissolved in the alkaline solution has a weight concentration of 9 to 22%.
8. The system for recovering carbon dioxide in an exhaust gas according to claim 6, further comprising:
a regeneration device to which the insoluble compound is supplied and which heats the insoluble compound to discharge carbon dioxide, thereby regenerating an alkali material, which configures the alkaline solution, from the insoluble compound.
9. A method for recovering carbon dioxide in an exhaust gas, comprising:
an absorption step which causes gas-liquid contact between the exhaust gas and an alkaline solution and absorbs the carbon dioxide contained in the exhaust gas by the alkaline solution to generate a reaction product insoluble compound;
a circulation step which causes repeatedly gas-liquid contact between the alkaline solution and the exhaust gas; and
a collection step which collects the insoluble compound contained in the alkaline solution.
10. The method for recovering carbon dioxide in an exhaust gas according to claim 9, further comprising:
a regeneration step which heats the insoluble compound collected in the collection step to discharge the carbon dioxide and regenerates an alkali material, which configures the alkaline solution, from the insoluble compound.
11. The method for recovering carbon dioxide in an exhaust gas according to claim 10, wherein the absorption step, the collection step, the circulation step and the regeneration step are repeated sequentially.