[Haskell-cafe] Proof format

R J rj248842 at hotmail.com
Wed May 19 09:12:16 EDT 2010


Is this how a rigorous Haskeller would lay out the proofs of the following theorems?  This is Bird 1.4.6.
(i)                           
Theorem:  (*) x = (* x)
Proof:
      (*) x  =    {definition of partial application}      \y -> x * y  =    {commutativity of "*"}      \y -> y * x  =    {definition of "(* x)"}      (* x)
(ii)
Theorem:  (+) x = (x +)
Proof:
      (+) x  =    {definition of partial application}      \y -> x + y  =    {definition of "(x +)"}      (x +)
(iii)
Theorem:  (-) x /= (- x)
Proof:
      (-) x  =    {definition of partial application}      \y -> x - y  /=   {definition of prefix negation, which is not a section}      (- x)
 		 	   		  
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