Description: Closure of square. (Contributed by NM, 10-Aug-1999)
Ref | Expression | ||
---|---|---|---|
Assertion | sqcl | ⊢ ( 𝐴 ∈ ℂ → ( 𝐴 ↑ 2 ) ∈ ℂ ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sqval | ⊢ ( 𝐴 ∈ ℂ → ( 𝐴 ↑ 2 ) = ( 𝐴 · 𝐴 ) ) | |
2 | mulcl | ⊢ ( ( 𝐴 ∈ ℂ ∧ 𝐴 ∈ ℂ ) → ( 𝐴 · 𝐴 ) ∈ ℂ ) | |
3 | 2 | anidms | ⊢ ( 𝐴 ∈ ℂ → ( 𝐴 · 𝐴 ) ∈ ℂ ) |
4 | 1 3 | eqeltrd | ⊢ ( 𝐴 ∈ ℂ → ( 𝐴 ↑ 2 ) ∈ ℂ ) |