Metamath Proof Explorer

Theorem sqge0d

Description: A square of a real is nonnegative. (Contributed by Mario Carneiro, 28-May-2016)

Ref Expression
Hypothesis resqcld.1 
|- ( ph -> A e. RR )
Assertion sqge0d 
|- ( ph -> 0 <_ ( A ^ 2 ) )

Proof

Step Hyp Ref Expression
1 resqcld.1 
 |-  ( ph -> A e. RR )
2 sqge0 
 |-  ( A e. RR -> 0 <_ ( A ^ 2 ) )
3 1 2 syl 
 |-  ( ph -> 0 <_ ( A ^ 2 ) )