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REAL AND COMPLEX NUMBERS
Integer sets
Principle of mathematical induction
nnne0i
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Theorem
nnne0i
Description:
A positive integer is nonzero (inference version).
(Contributed by
NM
, 25-Aug-1999)
Ref
Expression
Hypothesis
nngt0.1
⊢
A
∈
ℕ
Assertion
nnne0i
⊢
A
≠
0
Proof
Step
Hyp
Ref
Expression
1
nngt0.1
⊢
A
∈
ℕ
2
1
nnrei
⊢
A
∈
ℝ
3
1
nngt0i
⊢
0
<
A
4
2
3
gt0ne0ii
⊢
A
≠
0