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Computation

There is basically one computational operation, called beta-reduction.

(v.E1) E2 -> E1 [E2/v]

This means that the left hand expression is reduced to the right hand expression, which is E1 with E2 substituted for all free occurrences of v in E1.

example:

(v.v c) (x.x a)

= ((v.(v c)) (x.(x a)))

-> (v c)[x.(x a)/v]

= (x.(x a) c)

-> (x a)[c/x]

= (c a)


We can define ->* to be the transitive closure of ->



Alan Bond
1998-10-12