Description: "Is homeomorphic to" is symmetric. (Contributed by FL, 22-Feb-2007)
Ref | Expression | ||
---|---|---|---|
Assertion | hmphsymb | ⊢ ( 𝐽 ≃ 𝐾 ↔ 𝐾 ≃ 𝐽 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | hmphsym | ⊢ ( 𝐽 ≃ 𝐾 → 𝐾 ≃ 𝐽 ) | |
2 | hmphsym | ⊢ ( 𝐾 ≃ 𝐽 → 𝐽 ≃ 𝐾 ) | |
3 | 1 2 | impbii | ⊢ ( 𝐽 ≃ 𝐾 ↔ 𝐾 ≃ 𝐽 ) |