Metamath Proof Explorer


Theorem msqge0d

Description: A square is nonnegative. (Contributed by Mario Carneiro, 27-May-2016)

Ref Expression
Hypothesis leidd.1 φA
Assertion msqge0d φ0AA

Proof

Step Hyp Ref Expression
1 leidd.1 φA
2 msqge0 A0AA
3 1 2 syl φ0AA