Theorem cbvcsbv 2857

Description: Change the bound variable of a proper substitution into a class using implicit substitution. (Contributed by NM, 30-Sep-2008.) (Revised by Mario Carneiro, 13-Oct-2016.)

Hypothesis

Ref	Expression
cbvcsbv.1	|- ( x = y -> B = C )

Assertion

Ref	Expression
cbvcsbv	|- [_ A / x ]_ B = [_ A / y ]_ C

Distinct variable groups:   x, y   y, B   x, C

Allowed substitution hints:   A( x, y)   B( x)   C( y)

Proof of Theorem cbvcsbv

Step	Hyp	Ref	Expression
1		nfcv 2178	. 2 |- F/_ y B
2		nfcv 2178	. 2 |- F/_ x C
3		cbvcsbv.1	. 2 |- ( x = y -> B = C )
4	1, 2, 3	cbvcsb 2856	1 |- [_ A / x ]_ B = [_ A / y ]_ C

Syntax hints:   -> wi 4   = wceq 1243   [_csb 2852

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-io 630  ax-5 1336  ax-7 1337  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-8 1395  ax-10 1396  ax-11 1397  ax-i12 1398  ax-bndl 1399  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-tru 1246  df-nf 1350  df-sb 1646  df-clab 2027  df-cleq 2033  df-clel 2036  df-nfc 2167  df-sbc 2765  df-csb 2853

This theorem is referenced by: (None)