Description: The absolute value of a nonzero number is strictly positive. (Contributed by Mario Carneiro, 8-Sep-2014)
Ref | Expression | ||
---|---|---|---|
Hypotheses | abvf.a | ⊢ 𝐴 = ( AbsVal ‘ 𝑅 ) | |
abvf.b | ⊢ 𝐵 = ( Base ‘ 𝑅 ) | ||
abveq0.z | ⊢ 0 = ( 0g ‘ 𝑅 ) | ||
Assertion | abvgt0 | ⊢ ( ( 𝐹 ∈ 𝐴 ∧ 𝑋 ∈ 𝐵 ∧ 𝑋 ≠ 0 ) → 0 < ( 𝐹 ‘ 𝑋 ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | abvf.a | ⊢ 𝐴 = ( AbsVal ‘ 𝑅 ) | |
2 | abvf.b | ⊢ 𝐵 = ( Base ‘ 𝑅 ) | |
3 | abveq0.z | ⊢ 0 = ( 0g ‘ 𝑅 ) | |
4 | 1 2 | abvcl | ⊢ ( ( 𝐹 ∈ 𝐴 ∧ 𝑋 ∈ 𝐵 ) → ( 𝐹 ‘ 𝑋 ) ∈ ℝ ) |
5 | 4 | 3adant3 | ⊢ ( ( 𝐹 ∈ 𝐴 ∧ 𝑋 ∈ 𝐵 ∧ 𝑋 ≠ 0 ) → ( 𝐹 ‘ 𝑋 ) ∈ ℝ ) |
6 | 1 2 | abvge0 | ⊢ ( ( 𝐹 ∈ 𝐴 ∧ 𝑋 ∈ 𝐵 ) → 0 ≤ ( 𝐹 ‘ 𝑋 ) ) |
7 | 6 | 3adant3 | ⊢ ( ( 𝐹 ∈ 𝐴 ∧ 𝑋 ∈ 𝐵 ∧ 𝑋 ≠ 0 ) → 0 ≤ ( 𝐹 ‘ 𝑋 ) ) |
8 | 1 2 3 | abvne0 | ⊢ ( ( 𝐹 ∈ 𝐴 ∧ 𝑋 ∈ 𝐵 ∧ 𝑋 ≠ 0 ) → ( 𝐹 ‘ 𝑋 ) ≠ 0 ) |
9 | 5 7 8 | ne0gt0d | ⊢ ( ( 𝐹 ∈ 𝐴 ∧ 𝑋 ∈ 𝐵 ∧ 𝑋 ≠ 0 ) → 0 < ( 𝐹 ‘ 𝑋 ) ) |