| Step | Hyp | Ref
 | Expression | 
| 1 |   | suppofssd.3 | 
. . . . . . . 8
⊢ (𝜑 → 𝐹:𝐴⟶𝐵) | 
| 2 | 1 | ffnd 6716 | 
. . . . . . 7
⊢ (𝜑 → 𝐹 Fn 𝐴) | 
| 3 |   | suppofssd.4 | 
. . . . . . . 8
⊢ (𝜑 → 𝐺:𝐴⟶𝐵) | 
| 4 | 3 | ffnd 6716 | 
. . . . . . 7
⊢ (𝜑 → 𝐺 Fn 𝐴) | 
| 5 |   | suppofssd.1 | 
. . . . . . 7
⊢ (𝜑 → 𝐴 ∈ 𝑉) | 
| 6 |   | inidm 4207 | 
. . . . . . 7
⊢ (𝐴 ∩ 𝐴) = 𝐴 | 
| 7 |   | eqidd 2735 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑦 ∈ 𝐴) → (𝐹‘𝑦) = (𝐹‘𝑦)) | 
| 8 |   | eqidd 2735 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑦 ∈ 𝐴) → (𝐺‘𝑦) = (𝐺‘𝑦)) | 
| 9 | 2, 4, 5, 5, 6, 7, 8 | ofval 7689 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝑦 ∈ 𝐴) → ((𝐹 ∘f 𝑋𝐺)‘𝑦) = ((𝐹‘𝑦)𝑋(𝐺‘𝑦))) | 
| 10 | 9 | adantr 480 | 
. . . . 5
⊢ (((𝜑 ∧ 𝑦 ∈ 𝐴) ∧ (𝐺‘𝑦) = 𝑍) → ((𝐹 ∘f 𝑋𝐺)‘𝑦) = ((𝐹‘𝑦)𝑋(𝐺‘𝑦))) | 
| 11 |   | simpr 484 | 
. . . . . 6
⊢ (((𝜑 ∧ 𝑦 ∈ 𝐴) ∧ (𝐺‘𝑦) = 𝑍) → (𝐺‘𝑦) = 𝑍) | 
| 12 | 11 | oveq2d 7428 | 
. . . . 5
⊢ (((𝜑 ∧ 𝑦 ∈ 𝐴) ∧ (𝐺‘𝑦) = 𝑍) → ((𝐹‘𝑦)𝑋(𝐺‘𝑦)) = ((𝐹‘𝑦)𝑋𝑍)) | 
| 13 |   | suppofss2d.5 | 
. . . . . . . . 9
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐵) → (𝑥𝑋𝑍) = 𝑍) | 
| 14 | 13 | ralrimiva 3133 | 
. . . . . . . 8
⊢ (𝜑 → ∀𝑥 ∈ 𝐵 (𝑥𝑋𝑍) = 𝑍) | 
| 15 | 14 | adantr 480 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑦 ∈ 𝐴) → ∀𝑥 ∈ 𝐵 (𝑥𝑋𝑍) = 𝑍) | 
| 16 | 1 | ffvelcdmda 7083 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑦 ∈ 𝐴) → (𝐹‘𝑦) ∈ 𝐵) | 
| 17 |   | simpr 484 | 
. . . . . . . . . 10
⊢ (((𝜑 ∧ 𝑦 ∈ 𝐴) ∧ 𝑥 = (𝐹‘𝑦)) → 𝑥 = (𝐹‘𝑦)) | 
| 18 | 17 | oveq1d 7427 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ 𝑦 ∈ 𝐴) ∧ 𝑥 = (𝐹‘𝑦)) → (𝑥𝑋𝑍) = ((𝐹‘𝑦)𝑋𝑍)) | 
| 19 | 18 | eqeq1d 2736 | 
. . . . . . . 8
⊢ (((𝜑 ∧ 𝑦 ∈ 𝐴) ∧ 𝑥 = (𝐹‘𝑦)) → ((𝑥𝑋𝑍) = 𝑍 ↔ ((𝐹‘𝑦)𝑋𝑍) = 𝑍)) | 
| 20 | 16, 19 | rspcdv 3597 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑦 ∈ 𝐴) → (∀𝑥 ∈ 𝐵 (𝑥𝑋𝑍) = 𝑍 → ((𝐹‘𝑦)𝑋𝑍) = 𝑍)) | 
| 21 | 15, 20 | mpd 15 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝑦 ∈ 𝐴) → ((𝐹‘𝑦)𝑋𝑍) = 𝑍) | 
| 22 | 21 | adantr 480 | 
. . . . 5
⊢ (((𝜑 ∧ 𝑦 ∈ 𝐴) ∧ (𝐺‘𝑦) = 𝑍) → ((𝐹‘𝑦)𝑋𝑍) = 𝑍) | 
| 23 | 10, 12, 22 | 3eqtrd 2773 | 
. . . 4
⊢ (((𝜑 ∧ 𝑦 ∈ 𝐴) ∧ (𝐺‘𝑦) = 𝑍) → ((𝐹 ∘f 𝑋𝐺)‘𝑦) = 𝑍) | 
| 24 | 23 | ex 412 | 
. . 3
⊢ ((𝜑 ∧ 𝑦 ∈ 𝐴) → ((𝐺‘𝑦) = 𝑍 → ((𝐹 ∘f 𝑋𝐺)‘𝑦) = 𝑍)) | 
| 25 | 24 | ralrimiva 3133 | 
. 2
⊢ (𝜑 → ∀𝑦 ∈ 𝐴 ((𝐺‘𝑦) = 𝑍 → ((𝐹 ∘f 𝑋𝐺)‘𝑦) = 𝑍)) | 
| 26 | 2, 4, 5, 5, 6 | offn 7691 | 
. . 3
⊢ (𝜑 → (𝐹 ∘f 𝑋𝐺) Fn 𝐴) | 
| 27 |   | ssidd 3987 | 
. . 3
⊢ (𝜑 → 𝐴 ⊆ 𝐴) | 
| 28 |   | suppofssd.2 | 
. . 3
⊢ (𝜑 → 𝑍 ∈ 𝐵) | 
| 29 |   | suppfnss 8195 | 
. . 3
⊢ ((((𝐹 ∘f 𝑋𝐺) Fn 𝐴 ∧ 𝐺 Fn 𝐴) ∧ (𝐴 ⊆ 𝐴 ∧ 𝐴 ∈ 𝑉 ∧ 𝑍 ∈ 𝐵)) → (∀𝑦 ∈ 𝐴 ((𝐺‘𝑦) = 𝑍 → ((𝐹 ∘f 𝑋𝐺)‘𝑦) = 𝑍) → ((𝐹 ∘f 𝑋𝐺) supp 𝑍) ⊆ (𝐺 supp 𝑍))) | 
| 30 | 26, 4, 27, 5, 28, 29 | syl23anc 1378 | 
. 2
⊢ (𝜑 → (∀𝑦 ∈ 𝐴 ((𝐺‘𝑦) = 𝑍 → ((𝐹 ∘f 𝑋𝐺)‘𝑦) = 𝑍) → ((𝐹 ∘f 𝑋𝐺) supp 𝑍) ⊆ (𝐺 supp 𝑍))) | 
| 31 | 25, 30 | mpd 15 | 
1
⊢ (𝜑 → ((𝐹 ∘f 𝑋𝐺) supp 𝑍) ⊆ (𝐺 supp 𝑍)) |