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Question from Pierce's Types and Programming LanguagesOn page 56 at the top of the page he has the reduction: ( Î»x . x ( Î»x . x ) )( u r ) evaluates to u r ( Î»x . x ) My question is: I see how the lhs can be written as: (id(id))(ur) which is then (id)(ur). What I don't get is: (id)(ur) = (ur)(id). Is the point that the identity term is commutative in this context? Is this the same idea as the composition operation between functions in that the composition of two functions is generally not commutative, but the identity function is always commutative? By markt at 20080126 13:21  LtU Forum  previous forum topic  next forum topic  other blogs  3247 reads

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