CSCE 330 Fall 2007
Quiz 9
Assigned Thursday, 07-10-04
1. Recall that, in denotational semantics, the state is a triple <mem, i, o>.
(a) Which component(s) of the state are changed by a read instruction?
Answer: i, mem
(b) Which component(s) of the state are changed by a write instruction?
Answer: o (only)
(c) Which component(s) of the state are changed by an assignment?
Answer: mem
2. What is the denotational semantics of the following program, where the
initial input stream contains only the integer z?
read(n);
i := n+1;
write(i);
Hint: it is a very short answer!
Answer: <z+1>. Also acceptable: z+ 1, although technically the a nswer
is a sequence.
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