Theorem sseq2d 2973

Description: An equality deduction for the subclass relationship. (Contributed by NM, 14-Aug-1994.)

Hypothesis

Ref	Expression
sseq1d.1	|- ( ph -> A = B )

Assertion

Ref	Expression
sseq2d	|- ( ph -> ( C C_ A <-> C C_ B ) )

Proof of Theorem sseq2d

Step	Hyp	Ref	Expression
1		sseq1d.1	. 2 |- ( ph -> A = B )
2		sseq2 2967	. 2 |- ( A = B -> ( C C_ A <-> C C_ B ) )
3	1, 2	syl 14	1 |- ( ph -> ( C C_ A <-> C C_ B ) )

Syntax hints:   -> wi 4   <-> wb 98   = wceq 1243   C_ wss 2917

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-5 1336  ax-7 1337  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-8 1395  ax-11 1397  ax-4 1400  ax-17 1419  ax-i9 1423  ax-ial 1427  ax-i5r 1428  ax-ext 2022

This theorem depends on definitions:  df-bi 110  df-nf 1350  df-sb 1646  df-clab 2027  df-cleq 2033  df-clel 2036  df-in 2924  df-ss 2931

This theorem is referenced by:  sseq12d  2974  sseqtrd  2981  onsucsssucexmid  4252  sbcrel  4426  funimass2  4977  fnco  5007  fnssresb  5011  fnimaeq0  5020  foimacnv  5144  fvelimab  5229  ssimaexg  5235  fvmptss2  5247  rdgss  5970  frecsuclemdm  5988