Metamath Proof Explorer


Theorem sqvald

Description: Value of square. Inference version. (Contributed by Mario Carneiro, 28-May-2016)

Ref Expression
Hypothesis expcld.1 φ A
Assertion sqvald φ A 2 = A A

Proof

Step Hyp Ref Expression
1 expcld.1 φ A
2 sqval A A 2 = A A
3 1 2 syl φ A 2 = A A