Theorem eqsstrrid 3240

Description: B chained subclass and equality deduction. (Contributed by NM, 25-Apr-2004.)

Hypotheses

Ref	Expression
eqsstrrid.1	|- B = A
eqsstrrid.2	|- ( ph -> B C_ C )

Assertion

Ref	Expression
eqsstrrid	|- ( ph -> A C_ C )

Proof of Theorem eqsstrrid

Step	Hyp	Ref	Expression
1		eqsstrrid.1	. . 3 |- B = A
2	1	eqcomi 2209	. 2 |- A = B
3		eqsstrrid.2	. 2 |- ( ph -> B C_ C )
4	2, 3	eqsstrid 3239	1 |- ( ph -> A C_ C )

Syntax hints:   -> wi 4   = wceq 1373   C_ wss 3166

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-5 1470  ax-7 1471  ax-gen 1472  ax-ie1 1516  ax-ie2 1517  ax-8 1527  ax-11 1529  ax-4 1533  ax-17 1549  ax-i9 1553  ax-ial 1557  ax-i5r 1558  ax-ext 2187

This theorem depends on definitions:  df-bi 117  df-nf 1484  df-sb 1786  df-clab 2192  df-cleq 2198  df-clel 2201  df-in 3172  df-ss 3179

This theorem is referenced by:  abnexg  4493  relcnvtr  5202  resasplitss  5455  fimacnvdisj  5460  fimacnv  5709  f1ompt  5731  tfr1onlemres  6435  tfrcllemres  6448