Description: A quotient of a compact space is compact. (Contributed by Mario Carneiro, 24-Mar-2015)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | qtopcmp.1 | ⊢ 𝑋 = ∪ 𝐽 | |
| Assertion | qtopcmp | ⊢ ( ( 𝐽 ∈ Comp ∧ 𝐹 Fn 𝑋 ) → ( 𝐽 qTop 𝐹 ) ∈ Comp ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | qtopcmp.1 | ⊢ 𝑋 = ∪ 𝐽 | |
| 2 | cmptop | ⊢ ( 𝐽 ∈ Comp → 𝐽 ∈ Top ) | |
| 3 | eqid | ⊢ ∪ ( 𝐽 qTop 𝐹 ) = ∪ ( 𝐽 qTop 𝐹 ) | |
| 4 | 3 | cncmp | ⊢ ( ( 𝐽 ∈ Comp ∧ 𝐹 : 𝑋 –onto→ ∪ ( 𝐽 qTop 𝐹 ) ∧ 𝐹 ∈ ( 𝐽 Cn ( 𝐽 qTop 𝐹 ) ) ) → ( 𝐽 qTop 𝐹 ) ∈ Comp ) |
| 5 | 1 2 4 | qtopcmplem | ⊢ ( ( 𝐽 ∈ Comp ∧ 𝐹 Fn 𝑋 ) → ( 𝐽 qTop 𝐹 ) ∈ Comp ) |