Theorem eqsstrrd 3221

Description: Substitution of equality into a subclass relationship. (Contributed by NM, 25-Apr-2004.)

Hypotheses

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

Assertion

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

Proof of Theorem eqsstrrd

Step	Hyp	Ref	Expression
1		eqsstrrd.1	. . 3 |- ( ph -> B = A )
2	1	eqcomd 2202	. 2 |- ( ph -> A = B )
3		eqsstrrd.2	. 2 |- ( ph -> B C_ C )
4	2, 3	eqsstrd 3220	1 |- ( ph -> A C_ C )

Syntax hints:   -> wi 4   = wceq 1364   C_ wss 3157

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 1461  ax-7 1462  ax-gen 1463  ax-ie1 1507  ax-ie2 1508  ax-8 1518  ax-11 1520  ax-4 1524  ax-17 1540  ax-i9 1544  ax-ial 1548  ax-i5r 1549  ax-ext 2178

This theorem depends on definitions:  df-bi 117  df-nf 1475  df-sb 1777  df-clab 2183  df-cleq 2189  df-clel 2192  df-in 3163  df-ss 3170

This theorem is referenced by:  ssxpbm  5106  ssxp1  5107  ssxp2  5108  suppssof1  6157  tfrlemiubacc  6397  tfr1onlemubacc  6413  tfrcllemubacc  6426  oaword1  6538  phplem4dom  6932  fisseneq  7004  nnnninfeq2  7204  archnqq  7501  imasaddfnlemg  13016  resmhm2  13190  ringidss  13661  subrg1  13863  subrgdvds  13867  subrguss  13868  subrginv  13869  islss3  14011  lspsnneg  14052  epttop  14410  metequiv2  14816  limccnpcntop  14995  limccnp2lem  14996  limccnp2cntop  14997  nnsf  15736