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Database
REAL AND COMPLEX NUMBERS
Elementary trigonometry
The exponential, sine, and cosine functions
efne0d
Metamath Proof Explorer
Description: The exponential of a complex number is nonzero, deduction form.
(Contributed by NM , 13-Jan-2006) (Revised by Mario Carneiro , 29-Apr-2014) (Revised by SN , 25-Apr-2025)
Ref
Expression
Hypothesis
efne0d.1
⊢ φ → A ∈ ℂ
Assertion
efne0d
⊢ φ → e A ≠ 0
Proof
Step
Hyp
Ref
Expression
1
efne0d.1
⊢ φ → A ∈ ℂ
2
ax-1ne0
⊢ 1 ≠ 0
3
oveq1
⊢ e A = 0 → e A ⁢ e − A = 0 ⋅ e − A
4
efcan
⊢ A ∈ ℂ → e A ⁢ e − A = 1
5
1 4
syl
⊢ φ → e A ⁢ e − A = 1
6
1
negcld
⊢ φ → − A ∈ ℂ
7
6
efcld
⊢ φ → e − A ∈ ℂ
8
7
mul02d
⊢ φ → 0 ⋅ e − A = 0
9
5 8
eqeq12d
⊢ φ → e A ⁢ e − A = 0 ⋅ e − A ↔ 1 = 0
10
3 9
imbitrid
⊢ φ → e A = 0 → 1 = 0
11
10
necon3d
⊢ φ → 1 ≠ 0 → e A ≠ 0
12
2 11
mpi
⊢ φ → e A ≠ 0