Theorem sbf2 1187

Description: Substitution has no effect on a bound variable.

Assertion

Ref	Expression
sbf2	|- ([y / x]A.xph <-> A.xph)

Proof of Theorem sbf2

Step	Hyp	Ref	Expression
1		hba1 1003	. 2 |- (A.xph -> A.xA.xph)
2	1	sbf 1186	1 |- ([y / x]A.xph <-> A.xph)

Syntax hints:   <-> wb 146  A.wal 954  [wsbc 1170

This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-gen 963  ax-4 973  ax-5o 975  ax-6o 978  ax-9o 1123

This theorem depends on definitions:  df-bi 147  df-or 224  df-an 225  df-ex 981  df-sb 1172

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