Metamath Proof Explorer


Theorem smgrpmgm

Description: A semigroup is a magma. (Contributed by FL, 2-Nov-2009) (New usage is discouraged.)

Ref Expression
Hypothesis smgrpmgm.1
|- X = dom dom G
Assertion smgrpmgm
|- ( G e. SemiGrp -> G : ( X X. X ) --> X )

Proof

Step Hyp Ref Expression
1 smgrpmgm.1
 |-  X = dom dom G
2 1 issmgrpOLD
 |-  ( G e. SemiGrp -> ( G e. SemiGrp <-> ( G : ( X X. X ) --> X /\ A. x e. X A. y e. X A. z e. X ( ( x G y ) G z ) = ( x G ( y G z ) ) ) ) )
3 simpl
 |-  ( ( G : ( X X. X ) --> X /\ A. x e. X A. y e. X A. z e. X ( ( x G y ) G z ) = ( x G ( y G z ) ) ) -> G : ( X X. X ) --> X )
4 2 3 syl6bi
 |-  ( G e. SemiGrp -> ( G e. SemiGrp -> G : ( X X. X ) --> X ) )
5 4 pm2.43i
 |-  ( G e. SemiGrp -> G : ( X X. X ) --> X )