Theorem co01 5185

Description: Composition with the empty set. (Contributed by NM, 24-Apr-2004.)

Assertion

Ref	Expression
co01	|- ( (/) o. A ) = (/)

Proof of Theorem co01

Step	Hyp	Ref	Expression
1		cnv0 5074	. . . 4 |- `' (/) = (/)
2		cnvco 4852	. . . . 5 |- `' ( (/) o. A ) = ( `' A o. `' (/) )
3	1	coeq2i 4827	. . . . 5 |- ( `' A o. `' (/) ) = ( `' A o. (/) )
4		co02 5184	. . . . 5 |- ( `' A o. (/) ) = (/)
5	2, 3, 4	3eqtri 2221	. . . 4 |- `' ( (/) o. A ) = (/)
6	1, 5	eqtr4i 2220	. . 3 |- `' (/) = `' ( (/) o. A )
7	6	cnveqi 4842	. 2 |- `' `' (/) = `' `' ( (/) o. A )
8		rel0 4789	. . 3 |- Rel (/)
9		dfrel2 5121	. . 3 |- ( Rel (/) <-> `' `' (/) = (/) )
10	8, 9	mpbi 145	. 2 |- `' `' (/) = (/)
11		relco 5169	. . 3 |- Rel ( (/) o. A )
12		dfrel2 5121	. . 3 |- ( Rel ( (/) o. A ) <-> `' `' ( (/) o. A ) = ( (/) o. A ) )
13	11, 12	mpbi 145	. 2 |- `' `' ( (/) o. A ) = ( (/) o. A )
14	7, 10, 13	3eqtr3ri 2226	1 |- ( (/) o. A ) = (/)

Syntax hints:   = wceq 1364   (/)c0 3451   `'ccnv 4663   o. ccom 4668   Rel wrel 4669

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-in1 615  ax-in2 616  ax-io 710  ax-5 1461  ax-7 1462  ax-gen 1463  ax-ie1 1507  ax-ie2 1508  ax-8 1518  ax-10 1519  ax-11 1520  ax-i12 1521  ax-bndl 1523  ax-4 1524  ax-17 1540  ax-i9 1544  ax-ial 1548  ax-i5r 1549  ax-14 2170  ax-ext 2178  ax-sep 4152  ax-pow 4208  ax-pr 4243

This theorem depends on definitions:  df-bi 117  df-3an 982  df-tru 1367  df-fal 1370  df-nf 1475  df-sb 1777  df-eu 2048  df-mo 2049  df-clab 2183  df-cleq 2189  df-clel 2192  df-nfc 2328  df-ral 2480  df-rex 2481  df-v 2765  df-dif 3159  df-un 3161  df-in 3163  df-ss 3170  df-nul 3452  df-pw 3608  df-sn 3629  df-pr 3630  df-op 3632  df-br 4035  df-opab 4096  df-xp 4670  df-rel 4671  df-cnv 4672  df-co 4673

This theorem is referenced by: (None)