Description: Define the redundancy operator for propositions, cf. df-redund . (Contributed by Peter Mazsa, 23-Oct-2022)
Ref | Expression | ||
---|---|---|---|
Assertion | df-redundp | ⊢ ( redund ( 𝜑 , 𝜓 , 𝜒 ) ↔ ( ( 𝜑 → 𝜓 ) ∧ ( ( 𝜑 ∧ 𝜒 ) ↔ ( 𝜓 ∧ 𝜒 ) ) ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | wph | ⊢ 𝜑 | |
1 | wps | ⊢ 𝜓 | |
2 | wch | ⊢ 𝜒 | |
3 | 0 1 2 | wredundp | ⊢ redund ( 𝜑 , 𝜓 , 𝜒 ) |
4 | 0 1 | wi | ⊢ ( 𝜑 → 𝜓 ) |
5 | 0 2 | wa | ⊢ ( 𝜑 ∧ 𝜒 ) |
6 | 1 2 | wa | ⊢ ( 𝜓 ∧ 𝜒 ) |
7 | 5 6 | wb | ⊢ ( ( 𝜑 ∧ 𝜒 ) ↔ ( 𝜓 ∧ 𝜒 ) ) |
8 | 4 7 | wa | ⊢ ( ( 𝜑 → 𝜓 ) ∧ ( ( 𝜑 ∧ 𝜒 ) ↔ ( 𝜓 ∧ 𝜒 ) ) ) |
9 | 3 8 | wb | ⊢ ( redund ( 𝜑 , 𝜓 , 𝜒 ) ↔ ( ( 𝜑 → 𝜓 ) ∧ ( ( 𝜑 ∧ 𝜒 ) ↔ ( 𝜓 ∧ 𝜒 ) ) ) ) |