Theorem muccom 6135

Description: Cardinal multiplication commutes. Theorem XI.2.28 of [Rosser] p. 378. (Contributed by SF, 10-Mar-2015.)

Assertion

Ref	Expression
muccom	|- ((A e. NC /\ B e. NC ) -> (A ·c B) = (B ·c A))

Proof of Theorem muccom

Dummy variables x y are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		elncs 6120	. . . 4 |- (A e. NC <-> E.x A = Nc x)
2		elncs 6120	. . . 4 |- (B e. NC <-> E.y B = Nc y)
3	1, 2	anbi12i 678	. . 3 |- ((A e. NC /\ B e. NC ) <-> (E.x A = Nc x /\ E.y B = Nc y))
4		eeanv 1913	. . 3 |- (E.xE.y(A = Nc x /\ B = Nc y) <-> (E.x A = Nc x /\ E.y B = Nc y))
5	3, 4	bitr4i 243	. 2 |- ((A e. NC /\ B e. NC ) <-> E.xE.y(A = Nc x /\ B = Nc y))
6		vex 2863	. . . . . . 7 |- x e. _V
7		vex 2863	. . . . . . 7 |- y e. _V
8	6, 7	xpcomen 6053	. . . . . 6 |- (x X. y) ~~ (y X. x)
9	6, 7	xpex 5116	. . . . . . 7 |- (x X. y) e. _V
10	9	eqnc 6128	. . . . . 6 |- ( Nc (x X. y) = Nc (y X. x) <-> (x X. y) ~~ (y X. x))
11	8, 10	mpbir 200	. . . . 5 |- Nc (x X. y) = Nc (y X. x)
12	6, 7	mucnc 6132	. . . . 5 |- ( Nc x ·c Nc y) = Nc (x X. y)
13	7, 6	mucnc 6132	. . . . 5 |- ( Nc y ·c Nc x) = Nc (y X. x)
14	11, 12, 13	3eqtr4i 2383	. . . 4 |- ( Nc x ·c Nc y) = ( Nc y ·c Nc x)
15		oveq12 5533	. . . 4 |- ((A = Nc x /\ B = Nc y) -> (A ·c B) = ( Nc x ·c Nc y))
16		oveq12 5533	. . . . 5 |- ((B = Nc y /\ A = Nc x) -> (B ·c A) = ( Nc y ·c Nc x))
17	16	ancoms 439	. . . 4 |- ((A = Nc x /\ B = Nc y) -> (B ·c A) = ( Nc y ·c Nc x))
18	14, 15, 17	3eqtr4a 2411	. . 3 |- ((A = Nc x /\ B = Nc y) -> (A ·c B) = (B ·c A))
19	18	exlimivv 1635	. 2 |- (E.xE.y(A = Nc x /\ B = Nc y) -> (A ·c B) = (B ·c A))
20	5, 19	sylbi 187	1 |- ((A e. NC /\ B e. NC ) -> (A ·c B) = (B ·c A))

Syntax hints:   -> wi 4   /\ wa 358  E.wex 1541   = wceq 1642   e. wcel 1710   class class class wbr 4640   X. cxp 4771  (class class class)co 5526   ~~ cen 6029   NC cncs 6089   Nc cnc 6092   ·_c cmuc 6093

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1546  ax-5 1557  ax-17 1616  ax-9 1654  ax-8 1675  ax-13 1712  ax-14 1714  ax-6 1729  ax-7 1734  ax-11 1746  ax-12 1925  ax-ext 2334  ax-nin 4079  ax-xp 4080  ax-cnv 4081  ax-1c 4082  ax-sset 4083  ax-si 4084  ax-ins2 4085  ax-ins3 4086  ax-typlower 4087  ax-sn 4088

This theorem depends on definitions:  df-bi 177  df-or 359  df-an 360  df-3or 935  df-3an 936  df-nan 1288  df-tru 1319  df-ex 1542  df-nf 1545  df-sb 1649  df-eu 2208  df-mo 2209  df-clab 2340  df-cleq 2346  df-clel 2349  df-nfc 2479  df-ne 2519  df-ral 2620  df-rex 2621  df-reu 2622  df-rmo 2623  df-rab 2624  df-v 2862  df-sbc 3048  df-csb 3138  df-nin 3212  df-compl 3213  df-in 3214  df-un 3215  df-dif 3216  df-symdif 3217  df-ss 3260  df-pss 3262  df-nul 3552  df-if 3664  df-pw 3725  df-sn 3742  df-pr 3743  df-uni 3893  df-int 3928  df-iun 3972  df-opk 4059  df-1c 4137  df-pw1 4138  df-uni1 4139  df-xpk 4186  df-cnvk 4187  df-ins2k 4188  df-ins3k 4189  df-imak 4190  df-cok 4191  df-p6 4192  df-sik 4193  df-ssetk 4194  df-imagek 4195  df-idk 4196  df-iota 4340  df-0c 4378  df-addc 4379  df-nnc 4380  df-fin 4381  df-lefin 4441  df-ltfin 4442  df-ncfin 4443  df-tfin 4444  df-evenfin 4445  df-oddfin 4446  df-sfin 4447  df-spfin 4448  df-phi 4566  df-op 4567  df-proj1 4568  df-proj2 4569  df-opab 4624  df-br 4641  df-1st 4724  df-swap 4725  df-sset 4726  df-co 4727  df-ima 4728  df-si 4729  df-id 4768  df-xp 4785  df-cnv 4786  df-rn 4787  df-dm 4788  df-res 4789  df-fun 4790  df-fn 4791  df-f 4792  df-f1 4793  df-fo 4794  df-f1o 4795  df-fv 4796  df-2nd 4798  df-ov 5527  df-oprab 5529  df-mpt 5653  df-mpt2 5655  df-txp 5737  df-pprod 5739  df-ins2 5751  df-ins3 5753  df-image 5755  df-ins4 5757  df-si3 5759  df-funs 5761  df-fns 5763  df-cross 5765  df-trans 5900  df-sym 5909  df-er 5910  df-ec 5948  df-qs 5952  df-en 6030  df-ncs 6099  df-nc 6102  df-muc 6103

This theorem is referenced by:  addcdir  6252  muc0or  6253  lemuc2  6255