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Theorem iotabii 4361
 Description: Formula-building deduction rule for iota. (Contributed by Mario Carneiro, 2-Oct-2015.)
Hypothesis
Ref Expression
iotabii.1 (φψ)
Assertion
Ref Expression
iotabii (℩xφ) = (℩xψ)

Proof of Theorem iotabii
StepHypRef Expression
1 iotabi 4348 . 2 (x(φψ) → (℩xφ) = (℩xψ))
2 iotabii.1 . 2 (φψ)
31, 2mpg 1548 1 (℩xφ) = (℩xψ)
 Colors of variables: wff setvar class Syntax hints:   ↔ wb 176   = wceq 1642  ℩cio 4337 This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 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  ax-ext 2334 This theorem depends on definitions:  df-bi 177  df-or 359  df-an 360  df-tru 1319  df-ex 1542  df-nf 1545  df-sb 1649  df-clab 2340  df-cleq 2346  df-clel 2349  df-nfc 2478  df-rex 2620  df-uni 3892  df-iota 4339 This theorem is referenced by: (None)
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