Theorem cnvss 4885

Description: Subset theorem for converse. (Contributed by set.mm contributors, 22-Mar-1998.)

Assertion

Ref	Expression
cnvss	|- (A C_ B -> `'A C_ `'B)

Proof of Theorem cnvss

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

Step	Hyp	Ref	Expression
1		ssel 3267	. . . 4 |- (A C_ B -> (<.y, x>. e. A -> <.y, x>. e. B))
2		df-br 4640	. . . 4 |- (yAx <-> <.y, x>. e. A)
3		df-br 4640	. . . 4 |- (yBx <-> <.y, x>. e. B)
4	1, 2, 3	3imtr4g 261	. . 3 |- (A C_ B -> (yAx -> yBx))
5	4	ssopab2dv 4715	. 2 |- (A C_ B -> {<.x, y>. | yAx} C_ {<.x, y>. | yBx})
6		df-cnv 4785	. 2 |- `'A = {<.x, y>. | yAx}
7		df-cnv 4785	. 2 |- `'B = {<.x, y>. | yBx}
8	5, 6, 7	3sstr4g 3312	1 |- (A C_ B -> `'A C_ `'B)

Syntax hints:   -> wi 4   e. wcel 1710   C_ wss 3257  <.cop 4561  {copab 4622   class class class wbr 4639  `'ccnv 4771

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-6 1729  ax-7 1734  ax-11 1746  ax-12 1925  ax-ext 2334

This theorem depends on definitions:  df-bi 177  df-or 359  df-an 360  df-nan 1288  df-tru 1319  df-ex 1542  df-nf 1545  df-sb 1649  df-clab 2340  df-cleq 2346  df-clel 2349  df-nfc 2478  df-v 2861  df-nin 3211  df-compl 3212  df-in 3213  df-ss 3259  df-opab 4623  df-br 4640  df-cnv 4785

This theorem is referenced by:  cnveq  4886  rnss  4959  cnvtr  5098  funss  5126  funcnvuni  5161  funres11  5164  funcnvres  5165  foimacnv  5303