Theorem nfcrii 2221

Description: Consequence of the not-free predicate. (Contributed by Mario Carneiro, 11-Aug-2016.)

Hypothesis

Ref	Expression
nfcri.1	|- F/_ x A

Assertion

Ref	Expression
nfcrii	|- ( y e. A -> A. x y e. A )

Distinct variable group:   x, y

Allowed substitution hints:   A( x, y)

Proof of Theorem nfcrii

Dummy variable z is distinct from all other variables.

Step	Hyp	Ref	Expression
1		nfcri.1	. . . 4 |- F/_ x A
2		nfcr 2220	. . . 4 |- ( F/_ x A -> F/ x z e. A )
3	1, 2	ax-mp 7	. . 3 |- F/ x z e. A
4	3	nfri 1457	. 2 |- ( z e. A -> A. x z e. A )
5	4	hblem 2195	1 |- ( y e. A -> A. x y e. A )

Syntax hints:   -> wi 4   A.wal 1287   F/wnf 1394   e. wcel 1438   F/_wnfc 2215

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-io 665  ax-5 1381  ax-7 1382  ax-gen 1383  ax-ie1 1427  ax-ie2 1428  ax-8 1440  ax-10 1441  ax-11 1442  ax-i12 1443  ax-bndl 1444  ax-4 1445  ax-17 1464  ax-i9 1468  ax-ial 1472  ax-i5r 1473  ax-ext 2070

This theorem depends on definitions:  df-bi 115  df-nf 1395  df-sb 1693  df-cleq 2081  df-clel 2084  df-nfc 2217

This theorem is referenced by:  nfcri  2222