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sav08:program_memory_as_graph [2008/04/08 19:54] vkuncak |
sav08:program_memory_as_graph [2009/03/18 10:43] vkuncak |
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| Total functions (as in predicate logic, to make all variables well-defined). | Total functions (as in predicate logic, to make all variables well-defined). | ||
| + | |||
| + | We define: | ||
| + | next(null)=null | ||
| Special value (constant): $null \in Obj$ | Special value (constant): $null \in Obj$ | ||
| Line 13: | Line 16: | ||
| Local variable: $n, first \in Obj$ | Local variable: $n, first \in Obj$ | ||
| - | Values of $next,prev,n,first$ in the current state. | + | Program state as interpretation $I = (Obj,\alpha)$ in language ${\cal L} = \{ next, prev, null \}$. |
| + | |||
| + | Values of $next,prev,n,first$ in example state: | ||
| + | * before [[Insertion into Doubly-Linked List]] and | ||
| + | * after | ||
| + | |||
| + | In general, the declared fields determine | ||
| + | * function symbols, constants, and predicate symbols - if we use FOL | ||
| + | * variables, if we use HOL (predicate and function symbols become variables, like variables denoting elements) | ||