Theorem sbequ5 2128

Description: Substitution does not change an identical variable specifier. (Contributed by NM, 15-May-1993.)

Assertion

Ref	Expression
sbequ5

Proof of Theorem sbequ5

Step	Hyp	Ref	Expression
1		nfae 2056	. 2
2	1	sbf 2121	1

Syntax hints:  <->wb 184  A.wal 1393  [wsb 1739

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1618  ax-4 1631  ax-5 1704  ax-6 1747  ax-7 1790  ax-10 1837  ax-11 1842  ax-12 1854  ax-13 1999

This theorem depends on definitions:  df-bi 185  df-an 371  df-ex 1613  df-nf 1617  df-sb 1740