Description: Reverse of ibd . (Contributed by Rodolfo Medina, 30-Sep-2010)
Ref | Expression | ||
---|---|---|---|
Hypothesis | ibdr.1 | ⊢ ( 𝜑 → ( 𝜒 → ( 𝜓 ↔ 𝜒 ) ) ) | |
Assertion | ibdr | ⊢ ( 𝜑 → ( 𝜒 → 𝜓 ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ibdr.1 | ⊢ ( 𝜑 → ( 𝜒 → ( 𝜓 ↔ 𝜒 ) ) ) | |
2 | 1 | bicomdd | ⊢ ( 𝜑 → ( 𝜒 → ( 𝜒 ↔ 𝜓 ) ) ) |
3 | 2 | ibd | ⊢ ( 𝜑 → ( 𝜒 → 𝜓 ) ) |