Theorem frege54cor1b 39023

Description: Reflexive equality. (Contributed by RP, 24-Dec-2019.)

Assertion

Ref	Expression
frege54cor1b	⊢ [𝑥 / 𝑦]𝑦 = 𝑥

Proof of Theorem frege54cor1b

Step	Hyp	Ref	Expression
1		equsb1 2499	1 ⊢ [𝑥 / 𝑦]𝑦 = 𝑥

Syntax hints:  [wsb 2067

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1894  ax-4 1908  ax-5 2009  ax-6 2075  ax-7 2112  ax-12 2220  ax-13 2389

This theorem depends on definitions:  df-bi 199  df-an 387  df-ex 1879  df-sb 2068

This theorem is referenced by:  frege55lem2b  39025