Theorem co01 5258

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 5147	. . . 4 |- `' (/) = (/)
2		cnvco 4921	. . . . 5 |- `' ( (/) o. A ) = ( `' A o. `' (/) )
3	1	coeq2i 4896	. . . . 5 |- ( `' A o. `' (/) ) = ( `' A o. (/) )
4		co02 5257	. . . . 5 |- ( `' A o. (/) ) = (/)
5	2, 3, 4	3eqtri 2256	. . . 4 |- `' ( (/) o. A ) = (/)
6	1, 5	eqtr4i 2255	. . 3 |- `' (/) = `' ( (/) o. A )
7	6	cnveqi 4911	. 2 |- `' `' (/) = `' `' ( (/) o. A )
8		rel0 4858	. . 3 |- Rel (/)
9		dfrel2 5194	. . 3 |- ( Rel (/) <-> `' `' (/) = (/) )
10	8, 9	mpbi 145	. 2 |- `' `' (/) = (/)
11		relco 5242	. . 3 |- Rel ( (/) o. A )
12		dfrel2 5194	. . 3 |- ( Rel ( (/) o. A ) <-> `' `' ( (/) o. A ) = ( (/) o. A ) )
13	11, 12	mpbi 145	. 2 |- `' `' ( (/) o. A ) = ( (/) o. A )
14	7, 10, 13	3eqtr3ri 2261	1 |- ( (/) o. A ) = (/)

Syntax hints:   = wceq 1398   (/)c0 3496   `'ccnv 4730   o. ccom 4735   Rel wrel 4736

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 619  ax-in2 620  ax-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-14 2205  ax-ext 2213  ax-sep 4212  ax-pow 4270  ax-pr 4305

This theorem depends on definitions:  df-bi 117  df-3an 1007  df-tru 1401  df-fal 1404  df-nf 1510  df-sb 1811  df-eu 2082  df-mo 2083  df-clab 2218  df-cleq 2224  df-clel 2227  df-nfc 2364  df-ral 2516  df-rex 2517  df-v 2805  df-dif 3203  df-un 3205  df-in 3207  df-ss 3214  df-nul 3497  df-pw 3658  df-sn 3679  df-pr 3680  df-op 3682  df-br 4094  df-opab 4156  df-xp 4737  df-rel 4738  df-cnv 4739  df-co 4740

This theorem is referenced by: (None)