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Theorem sb4a 1923
Description: A version of sb4 2053 that doesn't require a distinctor antecedent. (Contributed by NM, 2-Feb-2007.)
Assertion
Ref Expression
sb4a ([y / x]yφx(x = yφ))

Proof of Theorem sb4a
StepHypRef Expression
1 sb1 1651 . 2 ([y / x]yφx(x = y yφ))
2 equs5a 1887 . 2 (x(x = y yφ) → x(x = yφ))
31, 2syl 15 1 ([y / x]yφx(x = yφ))
Colors of variables: wff setvar class
Syntax hints:  wi 4   wa 358  wal 1540  wex 1541  [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-11 1746
This theorem depends on definitions:  df-bi 177  df-an 360  df-ex 1542  df-nf 1545  df-sb 1649
This theorem is referenced by:  sb6f  2039  hbsb2a  2041
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