Description: Join three logical equivalences to form equivalence of implications. The following User's Proof is a Virtual Deduction proof completed automatically by the tools program completeusersproof.cmd, which invokes Mel L. O'Cat's mmj2 and Norm Megill's Metamath Proof Assistant. imbi13 is imbi13VD without virtual deductions and was automatically derived from imbi13VD .
1:: | |- (. ( ph <-> ps ) ->. ( ph <-> ps ) ). |
2:: | |- (. ( ph <-> ps ) ,. ( ch <-> th ) ->. ( ch <-> th ) ). |
3:: | |- (. ( ph <-> ps ) ,. ( ch <-> th ) ,. ( ta <-> et ) ->. ( ta <-> et ) ). |
4:2,3: | |- (. ( ph <-> ps ) ,. ( ch <-> th ) ,. ( ta <-> et ) ->. ( ( ch -> ta ) <-> ( th -> et ) ) ). |
5:1,4: | |- (. ( ph <-> ps ) ,. ( ch <-> th ) ,. ( ta <-> et ) ->. ( ( ph -> ( ch -> ta ) ) <-> ( ps -> ( th -> et ) ) ) ). |
6:5: | |- (. ( ph <-> ps ) ,. ( ch <-> th ) ->. ( ( ta <-> et ) -> ( ( ph -> ( ch -> ta ) ) <-> ( ps -> ( th -> et ) ) ) ) ). |
7:6: | |- (. ( ph <-> ps ) ->. ( ( ch <-> th ) -> ( ( ta <-> et ) -> ( ( ph -> ( ch -> ta ) ) <-> ( ps -> ( th -> et ) ) ) ) ) ). |
qed:7: | |- ( ( ph <-> ps ) -> ( ( ch <-> th ) -> ( ( ta <-> et ) -> ( ( ph -> ( ch -> ta ) ) <-> ( ps -> ( th -> et ) ) ) ) ) ) |
Ref | Expression | ||
---|---|---|---|
Assertion | imbi13VD | ⊢ ( ( 𝜑 ↔ 𝜓 ) → ( ( 𝜒 ↔ 𝜃 ) → ( ( 𝜏 ↔ 𝜂 ) → ( ( 𝜑 → ( 𝜒 → 𝜏 ) ) ↔ ( 𝜓 → ( 𝜃 → 𝜂 ) ) ) ) ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | idn1 | ⊢ ( ( 𝜑 ↔ 𝜓 ) ▶ ( 𝜑 ↔ 𝜓 ) ) | |
2 | idn2 | ⊢ ( ( 𝜑 ↔ 𝜓 ) , ( 𝜒 ↔ 𝜃 ) ▶ ( 𝜒 ↔ 𝜃 ) ) | |
3 | idn3 | ⊢ ( ( 𝜑 ↔ 𝜓 ) , ( 𝜒 ↔ 𝜃 ) , ( 𝜏 ↔ 𝜂 ) ▶ ( 𝜏 ↔ 𝜂 ) ) | |
4 | imbi12 | ⊢ ( ( 𝜒 ↔ 𝜃 ) → ( ( 𝜏 ↔ 𝜂 ) → ( ( 𝜒 → 𝜏 ) ↔ ( 𝜃 → 𝜂 ) ) ) ) | |
5 | 2 3 4 | e23 | ⊢ ( ( 𝜑 ↔ 𝜓 ) , ( 𝜒 ↔ 𝜃 ) , ( 𝜏 ↔ 𝜂 ) ▶ ( ( 𝜒 → 𝜏 ) ↔ ( 𝜃 → 𝜂 ) ) ) |
6 | imbi12 | ⊢ ( ( 𝜑 ↔ 𝜓 ) → ( ( ( 𝜒 → 𝜏 ) ↔ ( 𝜃 → 𝜂 ) ) → ( ( 𝜑 → ( 𝜒 → 𝜏 ) ) ↔ ( 𝜓 → ( 𝜃 → 𝜂 ) ) ) ) ) | |
7 | 1 5 6 | e13 | ⊢ ( ( 𝜑 ↔ 𝜓 ) , ( 𝜒 ↔ 𝜃 ) , ( 𝜏 ↔ 𝜂 ) ▶ ( ( 𝜑 → ( 𝜒 → 𝜏 ) ) ↔ ( 𝜓 → ( 𝜃 → 𝜂 ) ) ) ) |
8 | 7 | in3 | ⊢ ( ( 𝜑 ↔ 𝜓 ) , ( 𝜒 ↔ 𝜃 ) ▶ ( ( 𝜏 ↔ 𝜂 ) → ( ( 𝜑 → ( 𝜒 → 𝜏 ) ) ↔ ( 𝜓 → ( 𝜃 → 𝜂 ) ) ) ) ) |
9 | 8 | in2 | ⊢ ( ( 𝜑 ↔ 𝜓 ) ▶ ( ( 𝜒 ↔ 𝜃 ) → ( ( 𝜏 ↔ 𝜂 ) → ( ( 𝜑 → ( 𝜒 → 𝜏 ) ) ↔ ( 𝜓 → ( 𝜃 → 𝜂 ) ) ) ) ) ) |
10 | 9 | in1 | ⊢ ( ( 𝜑 ↔ 𝜓 ) → ( ( 𝜒 ↔ 𝜃 ) → ( ( 𝜏 ↔ 𝜂 ) → ( ( 𝜑 → ( 𝜒 → 𝜏 ) ) ↔ ( 𝜓 → ( 𝜃 → 𝜂 ) ) ) ) ) ) |