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Definition: Let f: An -> A and f': Bn -> B. We call h a homomorphism from A to B (with respect to f and f') if we have:

h: A ->hom(f,f') B : <=>
   h: A -> B /\ 
   (exists n in N:
      f: An -> A /\  f': Bn -> B /\ 
      (forall x in An: h(f(x0, ..., xn-1)) = f'(h(x0), ..., h(xn-1)))).
An isomorphism is a bijective homomorphism.
h: A ->iso(f,f') B : <=> h: A ->hom(f,f') B /\  h: A ->bijective B.

Author: Wolfgang Schreiner
Last Modification: December 7, 1999

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