Theorem hashtpgim 11320

Description: The size of an unordered triple of three different elements. (Contributed by Alexander van der Vekens, 10-Nov-2017.) (Revised by AV, 18-Sep-2021.) (Revised by Jim Kingdon, 17-Apr-2026.)

Assertion

Ref	Expression
hashtpgim	|- ( ( A e. U /\ B e. V /\ C e. W ) -> ( ( A =/= B /\ B =/= C /\ C =/= A ) -> (♯ ` { A , B , C } ) = 3 ) )

Proof of Theorem hashtpgim

Step	Hyp	Ref	Expression
1		df-tp 3717	. . . . 5 |- { A , B , C } = ( { A , B } u. { C } )
2	1	fveq2i 5701	. . . 4 |- (♯ ` { A , B , C } ) = (♯ ` ( { A , B } u. { C } ) )
3		simpl1 1031	. . . . . 6 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> A e. U )
4		simpl2 1032	. . . . . 6 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> B e. V )
5		simpr1 1034	. . . . . 6 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> A =/= B )
6		prfidisj 7239	. . . . . 6 |- ( ( A e. U /\ B e. V /\ A =/= B ) -> { A , B } e. Fin )
7	3, 4, 5, 6	syl3anc 1278	. . . . 5 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> { A , B } e. Fin )
8		simpl3 1033	. . . . . 6 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> C e. W )
9		snfig 7108	. . . . . 6 |- ( C e. W -> { C } e. Fin )
10	8, 9	syl 14	. . . . 5 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> { C } e. Fin )
11		dfsn2 3723	. . . . . . 7 |- { C } = { C , C }
12	11	ineq2i 3429	. . . . . 6 |- ( { A , B } i^i { C } ) = ( { A , B } i^i { C , C } )
13		simpr3 1036	. . . . . . . 8 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> C =/= A )
14	13	necomd 2506	. . . . . . 7 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> A =/= C )
15		simpr2 1035	. . . . . . 7 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> B =/= C )
16		disjpr2 3773	. . . . . . 7 |- ( ( ( A =/= C /\ B =/= C ) /\ ( A =/= C /\ B =/= C ) ) -> ( { A , B } i^i { C , C } ) = (/) )
17	14, 15, 14, 15, 16	syl22anc 1279	. . . . . 6 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> ( { A , B } i^i { C , C } ) = (/) )
18	12, 17	eqtrid 2283	. . . . 5 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> ( { A , B } i^i { C } ) = (/) )
19		hashun 11268	. . . . 5 |- ( ( { A , B } e. Fin /\ { C } e. Fin /\ ( { A , B } i^i { C } ) = (/) ) -> (♯ ` ( { A , B } u. { C } ) ) = ( (♯ ` { A , B } ) + (♯ ` { C } ) ) )
20	7, 10, 18, 19	syl3anc 1278	. . . 4 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> (♯ ` ( { A , B } u. { C } ) ) = ( (♯ ` { A , B } ) + (♯ ` { C } ) ) )
21	2, 20	eqtrid 2283	. . 3 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> (♯ ` { A , B , C } ) = ( (♯ ` { A , B } ) + (♯ ` { C } ) ) )
22		hashprg 11272	. . . . . . 7 |- ( ( A e. U /\ B e. V ) -> ( A =/= B <-> (♯ ` { A , B } ) = 2 ) )
23	3, 4, 22	syl2anc 415	. . . . . 6 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> ( A =/= B <-> (♯ ` { A , B } ) = 2 ) )
24	5, 23	mpbid 147	. . . . 5 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> (♯ ` { A , B } ) = 2 )
25		hashsng 11260	. . . . . 6 |- ( C e. W -> (♯ ` { C } ) = 1 )
26	8, 25	syl 14	. . . . 5 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> (♯ ` { C } ) = 1 )
27	24, 26	oveq12d 6106	. . . 4 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> ( (♯ ` { A , B } ) + (♯ ` { C } ) ) = ( 2 + 1 ) )
28		2p1e3 9448	. . . 4 |- ( 2 + 1 ) = 3
29	27, 28	eqtrdi 2287	. . 3 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> ( (♯ ` { A , B } ) + (♯ ` { C } ) ) = 3 )
30	21, 29	eqtrd 2271	. 2 |- ( ( ( A e. U /\ B e. V /\ C e. W ) /\ ( A =/= B /\ B =/= C /\ C =/= A ) ) -> (♯ ` { A , B , C } ) = 3 )
31	30	ex 115	1 |- ( ( A e. U /\ B e. V /\ C e. W ) -> ( ( A =/= B /\ B =/= C /\ C =/= A ) -> (♯ ` { A , B , C } ) = 3 ) )

This proof depends on syntax axioms:   -> wi 4   /\ wa 104   <-> wb 105   /\ w3a 1009   = wceq 1402   e. wcel 2209   =/= wne 2420   u. cun 3218   i^i cin 3219   (/)c0 3520   {csn 3709   {cpr 3710   {ctp 3711   ` cfv 5380  (class class class)co 6088   Fincfn 7027   1c1 8187   + caddc 8189   2c2 9365   3c3 9366  ♯chash 11237

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 623  ax-in2 624  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-14 2212  ax-ext 2220  ax-coll 4248  ax-sep 4251  ax-nul 4261  ax-pow 4313  ax-pr 4348  ax-un 4580  ax-setind 4686  ax-iinf 4737  ax-cnex 8277  ax-resscn 8278  ax-1cn 8279  ax-1re 8280  ax-icn 8281  ax-addcl 8282  ax-addrcl 8283  ax-mulcl 8284  ax-addcom 8286  ax-addass 8288  ax-distr 8290  ax-i2m1 8291  ax-0lt1 8292  ax-0id 8294  ax-rnegex 8295  ax-cnre 8297  ax-pre-ltirr 8298  ax-pre-ltwlin 8299  ax-pre-lttrn 8300  ax-pre-apti 8301  ax-pre-ltadd 8302

This proof depends on definitions:  df-bi 117  df-dc 847  df-3or 1010  df-3an 1011  df-tru 1405  df-fal 1408  df-nf 1514  df-sb 1816  df-eu 2089  df-mo 2090  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-ne 2421  df-nel 2516  df-ral 2533  df-rex 2534  df-reu 2535  df-rab 2537  df-v 2823  df-sbc 3052  df-csb 3148  df-dif 3222  df-un 3224  df-in 3226  df-ss 3233  df-nul 3521  df-if 3639  df-pw 3690  df-sn 3715  df-pr 3716  df-tp 3717  df-op 3718  df-uni 3936  df-int 3971  df-iun 4014  df-br 4132  df-opab 4194  df-mpt 4195  df-tr 4232  df-id 4440  df-iord 4513  df-on 4515  df-ilim 4516  df-suc 4518  df-iom 4740  df-xp 4782  df-rel 4783  df-cnv 4784  df-co 4785  df-dm 4786  df-rn 4787  df-res 4788  df-ima 4789  df-iota 5340  df-fun 5382  df-fn 5383  df-f 5384  df-f1 5385  df-fo 5386  df-f1o 5387  df-fv 5388  df-riota 6041  df-ov 6091  df-oprab 6092  df-mpo 6093  df-1st 6378  df-2nd 6379  df-recs 6580  df-irdg 6645  df-frec 6666  df-1o 6691  df-oadd 6695  df-er 6811  df-en 7028  df-dom 7029  df-fin 7030  df-pnf 8369  df-mnf 8370  df-xr 8371  df-ltxr 8372  df-le 8373  df-sub 8507  df-neg 8508  df-inn 9315  df-2 9373  df-3 9374  df-n0 9576  df-z 9657  df-uz 9939  df-fz 10430  df-ihash 11238

This theorem is used by:  hashtpg  11322