Theorem iscmn 14073

Description: The predicate "is a commutative monoid". (Contributed by Mario Carneiro, 6-Jan-2015.)

Hypotheses

Ref	Expression
iscmn.b	|- B = ( Base ` G )
iscmn.p	|- .+ = ( +g ` G )

Assertion

Ref	Expression
iscmn	|- ( G e. CMnd <-> ( G e. Mnd /\ A. x e. B A. y e. B ( x .+ y ) = ( y .+ x ) ) )

Distinct variable groups:   x, y, B   x, G, y

Allowed substitution hints:   .+ ( x, y)

Proof of Theorem iscmn

Dummy variable g is distinct from all other variables.

Step	Hyp	Ref	Expression
1		fveq2 5690	. . . . 5 |- ( g = G -> ( Base ` g ) = ( Base ` G ) )
2		iscmn.b	. . . . 5 |- B = ( Base ` G )
3	1, 2	eqtr4di 2289	. . . 4 |- ( g = G -> ( Base ` g ) = B )
4		raleq 2749	. . . . 5 |- ( ( Base ` g ) = B -> ( A. y e. ( Base ` g ) ( x ( +g ` g ) y ) = ( y ( +g ` g ) x ) <-> A. y e. B ( x ( +g ` g ) y ) = ( y ( +g ` g ) x ) ) )
5	4	raleqbi1dv 2761	. . . 4 |- ( ( Base ` g ) = B -> ( A. x e. ( Base ` g ) A. y e. ( Base ` g ) ( x ( +g ` g ) y ) = ( y ( +g ` g ) x ) <-> A. x e. B A. y e. B ( x ( +g ` g ) y ) = ( y ( +g ` g ) x ) ) )
6	3, 5	syl 14	. . 3 |- ( g = G -> ( A. x e. ( Base ` g ) A. y e. ( Base ` g ) ( x ( +g ` g ) y ) = ( y ( +g ` g ) x ) <-> A. x e. B A. y e. B ( x ( +g ` g ) y ) = ( y ( +g ` g ) x ) ) )
7		fveq2 5690	. . . . . . 7 |- ( g = G -> ( +g ` g ) = ( +g ` G ) )
8		iscmn.p	. . . . . . 7 |- .+ = ( +g ` G )
9	7, 8	eqtr4di 2289	. . . . . 6 |- ( g = G -> ( +g ` g ) = .+ )
10	9	oveqd 6092	. . . . 5 |- ( g = G -> ( x ( +g ` g ) y ) = ( x .+ y ) )
11	9	oveqd 6092	. . . . 5 |- ( g = G -> ( y ( +g ` g ) x ) = ( y .+ x ) )
12	10, 11	eqeq12d 2253	. . . 4 |- ( g = G -> ( ( x ( +g ` g ) y ) = ( y ( +g ` g ) x ) <-> ( x .+ y ) = ( y .+ x ) ) )
13	12	2ralbidv 2574	. . 3 |- ( g = G -> ( A. x e. B A. y e. B ( x ( +g ` g ) y ) = ( y ( +g ` g ) x ) <-> A. x e. B A. y e. B ( x .+ y ) = ( y .+ x ) ) )
14	6, 13	bitrd 188	. 2 |- ( g = G -> ( A. x e. ( Base ` g ) A. y e. ( Base ` g ) ( x ( +g ` g ) y ) = ( y ( +g ` g ) x ) <-> A. x e. B A. y e. B ( x .+ y ) = ( y .+ x ) ) )
15		df-cmn 14066	. 2 |- CMnd = { g e. Mnd | A. x e. ( Base ` g ) A. y e. ( Base ` g ) ( x ( +g ` g ) y ) = ( y ( +g ` g ) x ) }
16	14, 15	elrab2 2985	1 |- ( G e. CMnd <-> ( G e. Mnd /\ A. x e. B A. y e. B ( x .+ y ) = ( y .+ x ) ) )

Syntax hints:   /\ wa 104   <-> wb 105   = wceq 1402   e. wcel 2209   A.wral 2528   ` cfv 5372  (class class class)co 6075   Basecbs 13330   +g cplusg 13408   Mndcmnd 13706  CMndccmn 14064

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-ext 2220

This theorem depends on definitions:  df-bi 117  df-3an 1011  df-tru 1405  df-nf 1514  df-sb 1816  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-ral 2533  df-rex 2534  df-rab 2537  df-v 2823  df-un 3224  df-sn 3711  df-pr 3712  df-op 3714  df-uni 3931  df-br 4126  df-iota 5332  df-fv 5380  df-ov 6078  df-cmn 14066

This theorem is referenced by:  isabl2  14074  cmnpropd  14075  iscmnd  14078  cmnmnd  14081  cmncom  14082  cmnsubm  14089  ghmcmn  14108  iscrng2  14293