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sav07_lecture_3_skeleton [2007/03/20 18:14] wikiadmin |
sav07_lecture_3_skeleton [2007/03/20 18:22] wikiadmin |
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* represent programs using guarded command language, e.g. desugaring of 'if' into non-deterministic choice and assume | * represent programs using guarded command language, e.g. desugaring of 'if' into non-deterministic choice and assume | ||
* give meaning to guarded command language statements as relations | * give meaning to guarded command language statements as relations | ||
- | * we can represent relations using set comprehensions; if our program c has two state components, we can represent its meaning R( c ) as $\{((x_0,y_0),(x,y)) \mid F \}$, where F is some formula that has x,y,x_0,y_0 as free variables. | + | * we can represent relations using set comprehensions; if our program c has two state components, we can represent its meaning R( c ) as |
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+ | $\{((x_0,y_0),(x,y)) \mid F \}$ | ||
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+ | , where F is some formula that has x,y,x_0,y_0 as free variables. | ||
* this is what I mean by ''simple values'': later we will talk about modeling pointers and arrays, but we will still use this as a starting point. | * this is what I mean by ''simple values'': later we will talk about modeling pointers and arrays, but we will still use this as a starting point. | ||
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* efficient | * efficient | ||
* create formulas that we can effectively prove later | * create formulas that we can effectively prove later | ||
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What exactly do we prove about the formula R( c ) ? | What exactly do we prove about the formula R( c ) ? |