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Assignment and Contents Functions

These functions are taken from [McC62] with slight changes.

We work with a state vector tex2html_wrap_inline444 . It will be the situation s in our application, but we use tex2html_wrap_inline444 here in order to emphasize the mathematical notion. There are two functions.

tex2html_wrap_inline450 denotes the contents of the variable var in the state tex2html_wrap_inline444 .

tex2html_wrap_inline456 denotes the new state obtained by assigning the value value to the variable var in the state tex2html_wrap_inline444 and leaving all the other variables with the values they have in the state tex2html_wrap_inline444 .

We have the axioms


These axioms capture the notion that an assignment of a value produces a new state in which just that variable has its value changed. These functions are just what we need when we introduce frames.

John McCarthy
Thu Jan 30 13:14:14 PDT 1997