Description: The imaginary part of a complex number is real (closure law). (Contributed by Mario Carneiro, 29-May-2016)
Ref | Expression | ||
---|---|---|---|
Hypothesis | recld.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℂ ) | |
Assertion | imcld | ⊢ ( 𝜑 → ( ℑ ‘ 𝐴 ) ∈ ℝ ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | recld.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℂ ) | |
2 | imcl | ⊢ ( 𝐴 ∈ ℂ → ( ℑ ‘ 𝐴 ) ∈ ℝ ) | |
3 | 1 2 | syl | ⊢ ( 𝜑 → ( ℑ ‘ 𝐴 ) ∈ ℝ ) |