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REAL AND COMPLEX NUMBERS
Real and complex numbers - basic operations
Ordering on reals (cont.)
msqge0d
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lt0neg1d
Metamath Proof Explorer
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Unicode
Theorem
msqge0d
Description:
A square is nonnegative.
(Contributed by
Mario Carneiro
, 27-May-2016)
Ref
Expression
Hypothesis
leidd.1
⊢
φ
→
A
∈
ℝ
Assertion
msqge0d
⊢
φ
→
0
≤
A
⁢
A
Proof
Step
Hyp
Ref
Expression
1
leidd.1
⊢
φ
→
A
∈
ℝ
2
msqge0
⊢
A
∈
ℝ
→
0
≤
A
⁢
A
3
1
2
syl
⊢
φ
→
0
≤
A
⁢
A