1. A method for verifying a design of a circuit, comprising:
providing a model of the design;
providing a first property for the design, wherein the first property describes a first behavior;
checking the model using the first property and an environment of the design starting at a reset state until an example of the first behavior occurs;
providing a second property for the design, wherein the second property describes a second behavior;
checking the model using the second property and an environment of the design starting at a state when the example of the first behavior occurs; and
providing the state of the model of the design when the example of the first behavior occurs.
2. The method of claim 1, wherein providing the first property comprises:
providing a statement in a specification language stating that the first behavior does not occur.
3. The method of claim 2, wherein the environment of the design comprises one or more environment variables, and wherein checking the model using the first property comprises:
determining a set of values for the environment variables that causes the model of the design to show an example of the first behavior.
4. The method of claim 1, further comprising:
providing the environment of the design starting at the reset state.
5. The method of claim 1, further comprising:
providing the environment of the design starting at the state when the example of the first behavior occurs.
6. The method of claim 5:
wherein the environment of the design comprises one or more environment variables;
wherein the model of the design comprises one or more model variables; and
wherein providing the environment of the design starting at the state when the example of the first behavior occurs comprises at least one of the group consisting of:
describing the state when the example of the first behavior occurs; and each clock cycle preceding the example when the first behavior occurs.
7. An electronic circuit verified by the method of claim 1.
8. A computer program stored on a computer-readable medium for use by a processor for verifying a design of a circuit, comprising:
providing a model of the design;
providing a first property for the design, wherein the first property describes a first behavior;
checking the model using the first property and an environment of the design starting at a reset state until an example of the first behavior or occurs;
providing a second property for the design, wherein the second property describes a second behavior;
checking the model using the second property and an environment of the design starting at a state when the example of the behavior occurs; and
providing the state of the model of the design when the example of the first behavior occurs.
9. The computer program of claim 8, wherein providing the first property comprises:
providing a statement in a specification language stating that the first behavior does not occur.
10. The computer program of claim 9, wherein the environment of the design comprises one or more environment variables, and wherein checking the model using the first property comprises:
determining a set of values for the environment variables that causes the model of the design to show an example of the first behavior.
11. The computer program of claim 8, further comprising: providing the environment of the design starting at the reset state.
12. The computer program of claim 8, further comprising:
providing the environment of the design starting at the state when the example of the first behavior occurs.
13. The computer program of claim 12:
wherein the environment of the designs comprises one or more environment variables;
wherein the model of the design comprises one or more model variables; and
wherein providing the environment of be design at the state when the example of the first behavior occurs comprises at least one of the group consisting of:
describing the state when the example of the first behavior occurs; and
providing the values of the environment variables and the model variables in each clock cycle preceding the example, when the first behavior occurs.
14. An electronic circuit verified by the computer program of claim 8.
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 protective case for washing clothes, comprising:
a) an enclosed container made of hard plastics, said container having an open or closed position and being formed by a pair of bowl-shaped members similar in shape and opposite to each other, each of said bowl-shaped members having an about flat bottom portion and a side wall portion bent from a periphery of respective said about flat bottom portion;
b) hinge member for connecting said bowl-shaped members for opening and closing;
c) a pair of floating members similar in shape to each other and attached to respective said about flat bottom portion, said floating members being made of plastic having a specific gravity less than one and being symmetric with respect to a center of respective said about flat bottom portion; and
d) a plurality of water holes formed on a region of said respective side wall portion of said container.
2. A protective case as in claim 1, wherein:
a) said container includes a concave portion on an exterior surface; and
b) said floating member is attached to said concave portion.
3. A protective case as in claim 2, wherein a continuous surface is formed by a surface of said floating member and an outer surface of said container outside said concave portion.
4. A protective case as in claim 2, wherein roundness is formed on a corner portion of a projection corresponding to said concave portion.
5. A protective case as in claim 1, wherein a shock absorber is attached to a projection portion on an exterior surface of said container.