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Theorem bj-cleljusti 31856
Description: One direction of cleljust 1985, requiring only ax-1 6-- ax-5 1827 and ax8v1 1981. (Contributed by BJ, 31-Dec-2020.) (Proof modification is discouraged.)
Assertion
Ref Expression
bj-cleljusti (∃𝑧(𝑧 = 𝑥𝑧𝑦) → 𝑥𝑦)
Distinct variable groups:   𝑥,𝑧   𝑦,𝑧

Proof of Theorem bj-cleljusti
StepHypRef Expression
1 ax8v1 1981 . . 3 (𝑧 = 𝑥 → (𝑧𝑦𝑥𝑦))
21imp 444 . 2 ((𝑧 = 𝑥𝑧𝑦) → 𝑥𝑦)
32exlimiv 1845 1 (∃𝑧(𝑧 = 𝑥𝑧𝑦) → 𝑥𝑦)
Colors of variables: wff setvar class
Syntax hints:  wi 4  wa 383  wex 1695
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1713  ax-4 1728  ax-5 1827  ax-8 1979
This theorem depends on definitions:  df-bi 196  df-an 385  df-ex 1696
This theorem is referenced by: (None)
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