Proof of Theorem brcoffn
| Step | Hyp | Ref
| Expression |
| 1 | | brcoffn.c |
. . . 4
⊢ (𝜑 → 𝐶 Fn 𝑌) |
| 2 | | brcoffn.d |
. . . 4
⊢ (𝜑 → 𝐷:𝑋⟶𝑌) |
| 3 | | fnfco 6754 |
. . . 4
⊢ ((𝐶 Fn 𝑌 ∧ 𝐷:𝑋⟶𝑌) → (𝐶 ∘ 𝐷) Fn 𝑋) |
| 4 | 1, 2, 3 | syl2anc 584 |
. . 3
⊢ (𝜑 → (𝐶 ∘ 𝐷) Fn 𝑋) |
| 5 | | simpl 482 |
. . . 4
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋) → 𝜑) |
| 6 | | simpr 484 |
. . . 4
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋) → (𝐶 ∘ 𝐷) Fn 𝑋) |
| 7 | | brcoffn.r |
. . . . . 6
⊢ (𝜑 → 𝐴(𝐶 ∘ 𝐷)𝐵) |
| 8 | 5, 7 | syl 17 |
. . . . 5
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋) → 𝐴(𝐶 ∘ 𝐷)𝐵) |
| 9 | | fnbr 6657 |
. . . . 5
⊢ (((𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴(𝐶 ∘ 𝐷)𝐵) → 𝐴 ∈ 𝑋) |
| 10 | 6, 8, 9 | syl2anc 584 |
. . . 4
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋) → 𝐴 ∈ 𝑋) |
| 11 | 5, 6, 10 | 3jca 1128 |
. . 3
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋) → (𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴 ∈ 𝑋)) |
| 12 | 4, 11 | mpdan 687 |
. 2
⊢ (𝜑 → (𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴 ∈ 𝑋)) |
| 13 | 2 | 3ad2ant1 1133 |
. . . . . 6
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴 ∈ 𝑋) → 𝐷:𝑋⟶𝑌) |
| 14 | | simp3 1138 |
. . . . . 6
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴 ∈ 𝑋) → 𝐴 ∈ 𝑋) |
| 15 | | fvco3 6989 |
. . . . . 6
⊢ ((𝐷:𝑋⟶𝑌 ∧ 𝐴 ∈ 𝑋) → ((𝐶 ∘ 𝐷)‘𝐴) = (𝐶‘(𝐷‘𝐴))) |
| 16 | 13, 14, 15 | syl2anc 584 |
. . . . 5
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴 ∈ 𝑋) → ((𝐶 ∘ 𝐷)‘𝐴) = (𝐶‘(𝐷‘𝐴))) |
| 17 | 7 | 3ad2ant1 1133 |
. . . . . 6
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴 ∈ 𝑋) → 𝐴(𝐶 ∘ 𝐷)𝐵) |
| 18 | | fnbrfvb 6940 |
. . . . . . 7
⊢ (((𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴 ∈ 𝑋) → (((𝐶 ∘ 𝐷)‘𝐴) = 𝐵 ↔ 𝐴(𝐶 ∘ 𝐷)𝐵)) |
| 19 | 18 | 3adant1 1130 |
. . . . . 6
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴 ∈ 𝑋) → (((𝐶 ∘ 𝐷)‘𝐴) = 𝐵 ↔ 𝐴(𝐶 ∘ 𝐷)𝐵)) |
| 20 | 17, 19 | mpbird 257 |
. . . . 5
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴 ∈ 𝑋) → ((𝐶 ∘ 𝐷)‘𝐴) = 𝐵) |
| 21 | 16, 20 | eqtr3d 2771 |
. . . 4
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴 ∈ 𝑋) → (𝐶‘(𝐷‘𝐴)) = 𝐵) |
| 22 | | eqid 2734 |
. . . 4
⊢ (𝐷‘𝐴) = (𝐷‘𝐴) |
| 23 | 21, 22 | jctil 519 |
. . 3
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴 ∈ 𝑋) → ((𝐷‘𝐴) = (𝐷‘𝐴) ∧ (𝐶‘(𝐷‘𝐴)) = 𝐵)) |
| 24 | 13 | ffnd 6718 |
. . . . 5
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴 ∈ 𝑋) → 𝐷 Fn 𝑋) |
| 25 | | fnbrfvb 6940 |
. . . . 5
⊢ ((𝐷 Fn 𝑋 ∧ 𝐴 ∈ 𝑋) → ((𝐷‘𝐴) = (𝐷‘𝐴) ↔ 𝐴𝐷(𝐷‘𝐴))) |
| 26 | 24, 14, 25 | syl2anc 584 |
. . . 4
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴 ∈ 𝑋) → ((𝐷‘𝐴) = (𝐷‘𝐴) ↔ 𝐴𝐷(𝐷‘𝐴))) |
| 27 | 1 | 3ad2ant1 1133 |
. . . . 5
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴 ∈ 𝑋) → 𝐶 Fn 𝑌) |
| 28 | 13, 14 | ffvelcdmd 7086 |
. . . . 5
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴 ∈ 𝑋) → (𝐷‘𝐴) ∈ 𝑌) |
| 29 | | fnbrfvb 6940 |
. . . . 5
⊢ ((𝐶 Fn 𝑌 ∧ (𝐷‘𝐴) ∈ 𝑌) → ((𝐶‘(𝐷‘𝐴)) = 𝐵 ↔ (𝐷‘𝐴)𝐶𝐵)) |
| 30 | 27, 28, 29 | syl2anc 584 |
. . . 4
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴 ∈ 𝑋) → ((𝐶‘(𝐷‘𝐴)) = 𝐵 ↔ (𝐷‘𝐴)𝐶𝐵)) |
| 31 | 26, 30 | anbi12d 632 |
. . 3
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴 ∈ 𝑋) → (((𝐷‘𝐴) = (𝐷‘𝐴) ∧ (𝐶‘(𝐷‘𝐴)) = 𝐵) ↔ (𝐴𝐷(𝐷‘𝐴) ∧ (𝐷‘𝐴)𝐶𝐵))) |
| 32 | 23, 31 | mpbid 232 |
. 2
⊢ ((𝜑 ∧ (𝐶 ∘ 𝐷) Fn 𝑋 ∧ 𝐴 ∈ 𝑋) → (𝐴𝐷(𝐷‘𝐴) ∧ (𝐷‘𝐴)𝐶𝐵)) |
| 33 | 12, 32 | syl 17 |
1
⊢ (𝜑 → (𝐴𝐷(𝐷‘𝐴) ∧ (𝐷‘𝐴)𝐶𝐵)) |