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Theorem sbequ5 2031
Description: Substitution does not change an identical variable specifier. (Contributed by NM, 5-Aug-1993.)
Assertion
Ref Expression
sbequ5 ([w / z]x x = yx x = y)

Proof of Theorem sbequ5
StepHypRef Expression
1 nfae 1954 . 2 zx x = y
21sbf 2026 1 ([w / z]x x = yx x = y)
Colors of variables: wff setvar class
Syntax hints:  wb 176  wal 1540  [wsb 1648
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1546  ax-5 1557  ax-17 1616  ax-9 1654  ax-8 1675  ax-6 1729  ax-7 1734  ax-11 1746  ax-12 1925
This theorem depends on definitions:  df-bi 177  df-an 360  df-tru 1319  df-ex 1542  df-nf 1545  df-sb 1649
This theorem is referenced by:  sbal  2127
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