| Step | Hyp | Ref
 | Expression | 
| 1 |   | relco 5168 | 
. 2
⊢ Rel
(𝐺 ∘ 𝐹) | 
| 2 |   | funmpt 5296 | 
. . 3
⊢ Fun
(𝑥 ∈ 𝐴 ↦ 𝑇) | 
| 3 |   | funrel 5275 | 
. . 3
⊢ (Fun
(𝑥 ∈ 𝐴 ↦ 𝑇) → Rel (𝑥 ∈ 𝐴 ↦ 𝑇)) | 
| 4 | 2, 3 | ax-mp 5 | 
. 2
⊢ Rel
(𝑥 ∈ 𝐴 ↦ 𝑇) | 
| 5 |   | fmptco.1 | 
. . . . . . . . . . . . 13
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝑅 ∈ 𝐵) | 
| 6 |   | eqid 2196 | 
. . . . . . . . . . . . 13
⊢ (𝑥 ∈ 𝐴 ↦ 𝑅) = (𝑥 ∈ 𝐴 ↦ 𝑅) | 
| 7 | 5, 6 | fmptd 5716 | 
. . . . . . . . . . . 12
⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ 𝑅):𝐴⟶𝐵) | 
| 8 |   | fmptco.2 | 
. . . . . . . . . . . . 13
⊢ (𝜑 → 𝐹 = (𝑥 ∈ 𝐴 ↦ 𝑅)) | 
| 9 | 8 | feq1d 5394 | 
. . . . . . . . . . . 12
⊢ (𝜑 → (𝐹:𝐴⟶𝐵 ↔ (𝑥 ∈ 𝐴 ↦ 𝑅):𝐴⟶𝐵)) | 
| 10 | 7, 9 | mpbird 167 | 
. . . . . . . . . . 11
⊢ (𝜑 → 𝐹:𝐴⟶𝐵) | 
| 11 |   | ffun 5410 | 
. . . . . . . . . . 11
⊢ (𝐹:𝐴⟶𝐵 → Fun 𝐹) | 
| 12 | 10, 11 | syl 14 | 
. . . . . . . . . 10
⊢ (𝜑 → Fun 𝐹) | 
| 13 |   | funbrfv 5599 | 
. . . . . . . . . . 11
⊢ (Fun
𝐹 → (𝑧𝐹𝑢 → (𝐹‘𝑧) = 𝑢)) | 
| 14 | 13 | imp 124 | 
. . . . . . . . . 10
⊢ ((Fun
𝐹 ∧ 𝑧𝐹𝑢) → (𝐹‘𝑧) = 𝑢) | 
| 15 | 12, 14 | sylan 283 | 
. . . . . . . . 9
⊢ ((𝜑 ∧ 𝑧𝐹𝑢) → (𝐹‘𝑧) = 𝑢) | 
| 16 | 15 | eqcomd 2202 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑧𝐹𝑢) → 𝑢 = (𝐹‘𝑧)) | 
| 17 | 16 | a1d 22 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑧𝐹𝑢) → (𝑢𝐺𝑤 → 𝑢 = (𝐹‘𝑧))) | 
| 18 | 17 | expimpd 363 | 
. . . . . 6
⊢ (𝜑 → ((𝑧𝐹𝑢 ∧ 𝑢𝐺𝑤) → 𝑢 = (𝐹‘𝑧))) | 
| 19 | 18 | pm4.71rd 394 | 
. . . . 5
⊢ (𝜑 → ((𝑧𝐹𝑢 ∧ 𝑢𝐺𝑤) ↔ (𝑢 = (𝐹‘𝑧) ∧ (𝑧𝐹𝑢 ∧ 𝑢𝐺𝑤)))) | 
| 20 | 19 | exbidv 1839 | 
. . . 4
⊢ (𝜑 → (∃𝑢(𝑧𝐹𝑢 ∧ 𝑢𝐺𝑤) ↔ ∃𝑢(𝑢 = (𝐹‘𝑧) ∧ (𝑧𝐹𝑢 ∧ 𝑢𝐺𝑤)))) | 
| 21 |   | exsimpl 1631 | 
. . . . . . 7
⊢
(∃𝑢(𝑢 = (𝐹‘𝑧) ∧ (𝑧𝐹𝑢 ∧ 𝑢𝐺𝑤)) → ∃𝑢 𝑢 = (𝐹‘𝑧)) | 
| 22 |   | isset 2769 | 
. . . . . . 7
⊢ ((𝐹‘𝑧) ∈ V ↔ ∃𝑢 𝑢 = (𝐹‘𝑧)) | 
| 23 | 21, 22 | sylibr 134 | 
. . . . . 6
⊢
(∃𝑢(𝑢 = (𝐹‘𝑧) ∧ (𝑧𝐹𝑢 ∧ 𝑢𝐺𝑤)) → (𝐹‘𝑧) ∈ V) | 
| 24 | 23 | a1i 9 | 
. . . . 5
⊢ (𝜑 → (∃𝑢(𝑢 = (𝐹‘𝑧) ∧ (𝑧𝐹𝑢 ∧ 𝑢𝐺𝑤)) → (𝐹‘𝑧) ∈ V)) | 
| 25 | 12 | adantr 276 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑧 ∈ 𝐴) → Fun 𝐹) | 
| 26 |   | fdm 5413 | 
. . . . . . . . . . 11
⊢ (𝐹:𝐴⟶𝐵 → dom 𝐹 = 𝐴) | 
| 27 | 10, 26 | syl 14 | 
. . . . . . . . . 10
⊢ (𝜑 → dom 𝐹 = 𝐴) | 
| 28 | 27 | eleq2d 2266 | 
. . . . . . . . 9
⊢ (𝜑 → (𝑧 ∈ dom 𝐹 ↔ 𝑧 ∈ 𝐴)) | 
| 29 | 28 | biimpar 297 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑧 ∈ 𝐴) → 𝑧 ∈ dom 𝐹) | 
| 30 |   | funfvex 5575 | 
. . . . . . . 8
⊢ ((Fun
𝐹 ∧ 𝑧 ∈ dom 𝐹) → (𝐹‘𝑧) ∈ V) | 
| 31 | 25, 29, 30 | syl2anc 411 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑧 ∈ 𝐴) → (𝐹‘𝑧) ∈ V) | 
| 32 | 31 | adantrr 479 | 
. . . . . 6
⊢ ((𝜑 ∧ (𝑧 ∈ 𝐴 ∧ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇)) → (𝐹‘𝑧) ∈ V) | 
| 33 | 32 | ex 115 | 
. . . . 5
⊢ (𝜑 → ((𝑧 ∈ 𝐴 ∧ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇) → (𝐹‘𝑧) ∈ V)) | 
| 34 |   | breq2 4037 | 
. . . . . . . . 9
⊢ (𝑢 = (𝐹‘𝑧) → (𝑧𝐹𝑢 ↔ 𝑧𝐹(𝐹‘𝑧))) | 
| 35 |   | breq1 4036 | 
. . . . . . . . 9
⊢ (𝑢 = (𝐹‘𝑧) → (𝑢𝐺𝑤 ↔ (𝐹‘𝑧)𝐺𝑤)) | 
| 36 | 34, 35 | anbi12d 473 | 
. . . . . . . 8
⊢ (𝑢 = (𝐹‘𝑧) → ((𝑧𝐹𝑢 ∧ 𝑢𝐺𝑤) ↔ (𝑧𝐹(𝐹‘𝑧) ∧ (𝐹‘𝑧)𝐺𝑤))) | 
| 37 | 36 | ceqsexgv 2893 | 
. . . . . . 7
⊢ ((𝐹‘𝑧) ∈ V → (∃𝑢(𝑢 = (𝐹‘𝑧) ∧ (𝑧𝐹𝑢 ∧ 𝑢𝐺𝑤)) ↔ (𝑧𝐹(𝐹‘𝑧) ∧ (𝐹‘𝑧)𝐺𝑤))) | 
| 38 |   | funfvbrb 5675 | 
. . . . . . . . . . 11
⊢ (Fun
𝐹 → (𝑧 ∈ dom 𝐹 ↔ 𝑧𝐹(𝐹‘𝑧))) | 
| 39 | 12, 38 | syl 14 | 
. . . . . . . . . 10
⊢ (𝜑 → (𝑧 ∈ dom 𝐹 ↔ 𝑧𝐹(𝐹‘𝑧))) | 
| 40 | 39, 28 | bitr3d 190 | 
. . . . . . . . 9
⊢ (𝜑 → (𝑧𝐹(𝐹‘𝑧) ↔ 𝑧 ∈ 𝐴)) | 
| 41 | 8 | fveq1d 5560 | 
. . . . . . . . . 10
⊢ (𝜑 → (𝐹‘𝑧) = ((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑧)) | 
| 42 |   | fmptco.3 | 
. . . . . . . . . 10
⊢ (𝜑 → 𝐺 = (𝑦 ∈ 𝐵 ↦ 𝑆)) | 
| 43 |   | eqidd 2197 | 
. . . . . . . . . 10
⊢ (𝜑 → 𝑤 = 𝑤) | 
| 44 | 41, 42, 43 | breq123d 4047 | 
. . . . . . . . 9
⊢ (𝜑 → ((𝐹‘𝑧)𝐺𝑤 ↔ ((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑧)(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤)) | 
| 45 | 40, 44 | anbi12d 473 | 
. . . . . . . 8
⊢ (𝜑 → ((𝑧𝐹(𝐹‘𝑧) ∧ (𝐹‘𝑧)𝐺𝑤) ↔ (𝑧 ∈ 𝐴 ∧ ((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑧)(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤))) | 
| 46 |   | nfcv 2339 | 
. . . . . . . . . . 11
⊢
Ⅎ𝑥𝑧 | 
| 47 |   | nfv 1542 | 
. . . . . . . . . . . 12
⊢
Ⅎ𝑥𝜑 | 
| 48 |   | nffvmpt1 5569 | 
. . . . . . . . . . . . . 14
⊢
Ⅎ𝑥((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑧) | 
| 49 |   | nfcv 2339 | 
. . . . . . . . . . . . . 14
⊢
Ⅎ𝑥(𝑦 ∈ 𝐵 ↦ 𝑆) | 
| 50 |   | nfcv 2339 | 
. . . . . . . . . . . . . 14
⊢
Ⅎ𝑥𝑤 | 
| 51 | 48, 49, 50 | nfbr 4079 | 
. . . . . . . . . . . . 13
⊢
Ⅎ𝑥((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑧)(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤 | 
| 52 |   | nfcsb1v 3117 | 
. . . . . . . . . . . . . 14
⊢
Ⅎ𝑥⦋𝑧 / 𝑥⦌𝑇 | 
| 53 | 52 | nfeq2 2351 | 
. . . . . . . . . . . . 13
⊢
Ⅎ𝑥 𝑤 = ⦋𝑧 / 𝑥⦌𝑇 | 
| 54 | 51, 53 | nfbi 1603 | 
. . . . . . . . . . . 12
⊢
Ⅎ𝑥(((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑧)(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤 ↔ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇) | 
| 55 | 47, 54 | nfim 1586 | 
. . . . . . . . . . 11
⊢
Ⅎ𝑥(𝜑 → (((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑧)(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤 ↔ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇)) | 
| 56 |   | fveq2 5558 | 
. . . . . . . . . . . . . 14
⊢ (𝑥 = 𝑧 → ((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑥) = ((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑧)) | 
| 57 | 56 | breq1d 4043 | 
. . . . . . . . . . . . 13
⊢ (𝑥 = 𝑧 → (((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑥)(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤 ↔ ((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑧)(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤)) | 
| 58 |   | csbeq1a 3093 | 
. . . . . . . . . . . . . 14
⊢ (𝑥 = 𝑧 → 𝑇 = ⦋𝑧 / 𝑥⦌𝑇) | 
| 59 | 58 | eqeq2d 2208 | 
. . . . . . . . . . . . 13
⊢ (𝑥 = 𝑧 → (𝑤 = 𝑇 ↔ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇)) | 
| 60 | 57, 59 | bibi12d 235 | 
. . . . . . . . . . . 12
⊢ (𝑥 = 𝑧 → ((((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑥)(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤 ↔ 𝑤 = 𝑇) ↔ (((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑧)(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤 ↔ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇))) | 
| 61 | 60 | imbi2d 230 | 
. . . . . . . . . . 11
⊢ (𝑥 = 𝑧 → ((𝜑 → (((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑥)(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤 ↔ 𝑤 = 𝑇)) ↔ (𝜑 → (((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑧)(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤 ↔ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇)))) | 
| 62 |   | vex 2766 | 
. . . . . . . . . . . . . 14
⊢ 𝑤 ∈ V | 
| 63 |   | simpl 109 | 
. . . . . . . . . . . . . . . . 17
⊢ ((𝑦 = 𝑅 ∧ 𝑢 = 𝑤) → 𝑦 = 𝑅) | 
| 64 | 63 | eleq1d 2265 | 
. . . . . . . . . . . . . . . 16
⊢ ((𝑦 = 𝑅 ∧ 𝑢 = 𝑤) → (𝑦 ∈ 𝐵 ↔ 𝑅 ∈ 𝐵)) | 
| 65 |   | simpr 110 | 
. . . . . . . . . . . . . . . . 17
⊢ ((𝑦 = 𝑅 ∧ 𝑢 = 𝑤) → 𝑢 = 𝑤) | 
| 66 |   | fmptco.4 | 
. . . . . . . . . . . . . . . . . 18
⊢ (𝑦 = 𝑅 → 𝑆 = 𝑇) | 
| 67 | 66 | adantr 276 | 
. . . . . . . . . . . . . . . . 17
⊢ ((𝑦 = 𝑅 ∧ 𝑢 = 𝑤) → 𝑆 = 𝑇) | 
| 68 | 65, 67 | eqeq12d 2211 | 
. . . . . . . . . . . . . . . 16
⊢ ((𝑦 = 𝑅 ∧ 𝑢 = 𝑤) → (𝑢 = 𝑆 ↔ 𝑤 = 𝑇)) | 
| 69 | 64, 68 | anbi12d 473 | 
. . . . . . . . . . . . . . 15
⊢ ((𝑦 = 𝑅 ∧ 𝑢 = 𝑤) → ((𝑦 ∈ 𝐵 ∧ 𝑢 = 𝑆) ↔ (𝑅 ∈ 𝐵 ∧ 𝑤 = 𝑇))) | 
| 70 |   | df-mpt 4096 | 
. . . . . . . . . . . . . . 15
⊢ (𝑦 ∈ 𝐵 ↦ 𝑆) = {〈𝑦, 𝑢〉 ∣ (𝑦 ∈ 𝐵 ∧ 𝑢 = 𝑆)} | 
| 71 | 69, 70 | brabga 4298 | 
. . . . . . . . . . . . . 14
⊢ ((𝑅 ∈ 𝐵 ∧ 𝑤 ∈ V) → (𝑅(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤 ↔ (𝑅 ∈ 𝐵 ∧ 𝑤 = 𝑇))) | 
| 72 | 5, 62, 71 | sylancl 413 | 
. . . . . . . . . . . . 13
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → (𝑅(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤 ↔ (𝑅 ∈ 𝐵 ∧ 𝑤 = 𝑇))) | 
| 73 |   | simpr 110 | 
. . . . . . . . . . . . . . 15
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ 𝐴) | 
| 74 | 6 | fvmpt2 5645 | 
. . . . . . . . . . . . . . 15
⊢ ((𝑥 ∈ 𝐴 ∧ 𝑅 ∈ 𝐵) → ((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑥) = 𝑅) | 
| 75 | 73, 5, 74 | syl2anc 411 | 
. . . . . . . . . . . . . 14
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → ((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑥) = 𝑅) | 
| 76 | 75 | breq1d 4043 | 
. . . . . . . . . . . . 13
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → (((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑥)(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤 ↔ 𝑅(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤)) | 
| 77 | 5 | biantrurd 305 | 
. . . . . . . . . . . . 13
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → (𝑤 = 𝑇 ↔ (𝑅 ∈ 𝐵 ∧ 𝑤 = 𝑇))) | 
| 78 | 72, 76, 77 | 3bitr4d 220 | 
. . . . . . . . . . . 12
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → (((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑥)(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤 ↔ 𝑤 = 𝑇)) | 
| 79 | 78 | expcom 116 | 
. . . . . . . . . . 11
⊢ (𝑥 ∈ 𝐴 → (𝜑 → (((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑥)(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤 ↔ 𝑤 = 𝑇))) | 
| 80 | 46, 55, 61, 79 | vtoclgaf 2829 | 
. . . . . . . . . 10
⊢ (𝑧 ∈ 𝐴 → (𝜑 → (((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑧)(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤 ↔ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇))) | 
| 81 | 80 | impcom 125 | 
. . . . . . . . 9
⊢ ((𝜑 ∧ 𝑧 ∈ 𝐴) → (((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑧)(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤 ↔ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇)) | 
| 82 | 81 | pm5.32da 452 | 
. . . . . . . 8
⊢ (𝜑 → ((𝑧 ∈ 𝐴 ∧ ((𝑥 ∈ 𝐴 ↦ 𝑅)‘𝑧)(𝑦 ∈ 𝐵 ↦ 𝑆)𝑤) ↔ (𝑧 ∈ 𝐴 ∧ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇))) | 
| 83 | 45, 82 | bitrd 188 | 
. . . . . . 7
⊢ (𝜑 → ((𝑧𝐹(𝐹‘𝑧) ∧ (𝐹‘𝑧)𝐺𝑤) ↔ (𝑧 ∈ 𝐴 ∧ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇))) | 
| 84 | 37, 83 | sylan9bbr 463 | 
. . . . . 6
⊢ ((𝜑 ∧ (𝐹‘𝑧) ∈ V) → (∃𝑢(𝑢 = (𝐹‘𝑧) ∧ (𝑧𝐹𝑢 ∧ 𝑢𝐺𝑤)) ↔ (𝑧 ∈ 𝐴 ∧ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇))) | 
| 85 | 84 | ex 115 | 
. . . . 5
⊢ (𝜑 → ((𝐹‘𝑧) ∈ V → (∃𝑢(𝑢 = (𝐹‘𝑧) ∧ (𝑧𝐹𝑢 ∧ 𝑢𝐺𝑤)) ↔ (𝑧 ∈ 𝐴 ∧ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇)))) | 
| 86 | 24, 33, 85 | pm5.21ndd 706 | 
. . . 4
⊢ (𝜑 → (∃𝑢(𝑢 = (𝐹‘𝑧) ∧ (𝑧𝐹𝑢 ∧ 𝑢𝐺𝑤)) ↔ (𝑧 ∈ 𝐴 ∧ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇))) | 
| 87 | 20, 86 | bitrd 188 | 
. . 3
⊢ (𝜑 → (∃𝑢(𝑧𝐹𝑢 ∧ 𝑢𝐺𝑤) ↔ (𝑧 ∈ 𝐴 ∧ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇))) | 
| 88 |   | vex 2766 | 
. . . 4
⊢ 𝑧 ∈ V | 
| 89 | 88, 62 | opelco 4838 | 
. . 3
⊢
(〈𝑧, 𝑤〉 ∈ (𝐺 ∘ 𝐹) ↔ ∃𝑢(𝑧𝐹𝑢 ∧ 𝑢𝐺𝑤)) | 
| 90 |   | df-mpt 4096 | 
. . . . 5
⊢ (𝑥 ∈ 𝐴 ↦ 𝑇) = {〈𝑥, 𝑣〉 ∣ (𝑥 ∈ 𝐴 ∧ 𝑣 = 𝑇)} | 
| 91 | 90 | eleq2i 2263 | 
. . . 4
⊢
(〈𝑧, 𝑤〉 ∈ (𝑥 ∈ 𝐴 ↦ 𝑇) ↔ 〈𝑧, 𝑤〉 ∈ {〈𝑥, 𝑣〉 ∣ (𝑥 ∈ 𝐴 ∧ 𝑣 = 𝑇)}) | 
| 92 |   | nfv 1542 | 
. . . . . 6
⊢
Ⅎ𝑥 𝑧 ∈ 𝐴 | 
| 93 | 52 | nfeq2 2351 | 
. . . . . 6
⊢
Ⅎ𝑥 𝑣 = ⦋𝑧 / 𝑥⦌𝑇 | 
| 94 | 92, 93 | nfan 1579 | 
. . . . 5
⊢
Ⅎ𝑥(𝑧 ∈ 𝐴 ∧ 𝑣 = ⦋𝑧 / 𝑥⦌𝑇) | 
| 95 |   | nfv 1542 | 
. . . . 5
⊢
Ⅎ𝑣(𝑧 ∈ 𝐴 ∧ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇) | 
| 96 |   | eleq1 2259 | 
. . . . . 6
⊢ (𝑥 = 𝑧 → (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴)) | 
| 97 | 58 | eqeq2d 2208 | 
. . . . . 6
⊢ (𝑥 = 𝑧 → (𝑣 = 𝑇 ↔ 𝑣 = ⦋𝑧 / 𝑥⦌𝑇)) | 
| 98 | 96, 97 | anbi12d 473 | 
. . . . 5
⊢ (𝑥 = 𝑧 → ((𝑥 ∈ 𝐴 ∧ 𝑣 = 𝑇) ↔ (𝑧 ∈ 𝐴 ∧ 𝑣 = ⦋𝑧 / 𝑥⦌𝑇))) | 
| 99 |   | eqeq1 2203 | 
. . . . . 6
⊢ (𝑣 = 𝑤 → (𝑣 = ⦋𝑧 / 𝑥⦌𝑇 ↔ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇)) | 
| 100 | 99 | anbi2d 464 | 
. . . . 5
⊢ (𝑣 = 𝑤 → ((𝑧 ∈ 𝐴 ∧ 𝑣 = ⦋𝑧 / 𝑥⦌𝑇) ↔ (𝑧 ∈ 𝐴 ∧ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇))) | 
| 101 | 94, 95, 88, 62, 98, 100 | opelopabf 4309 | 
. . . 4
⊢
(〈𝑧, 𝑤〉 ∈ {〈𝑥, 𝑣〉 ∣ (𝑥 ∈ 𝐴 ∧ 𝑣 = 𝑇)} ↔ (𝑧 ∈ 𝐴 ∧ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇)) | 
| 102 | 91, 101 | bitri 184 | 
. . 3
⊢
(〈𝑧, 𝑤〉 ∈ (𝑥 ∈ 𝐴 ↦ 𝑇) ↔ (𝑧 ∈ 𝐴 ∧ 𝑤 = ⦋𝑧 / 𝑥⦌𝑇)) | 
| 103 | 87, 89, 102 | 3bitr4g 223 | 
. 2
⊢ (𝜑 → (〈𝑧, 𝑤〉 ∈ (𝐺 ∘ 𝐹) ↔ 〈𝑧, 𝑤〉 ∈ (𝑥 ∈ 𝐴 ↦ 𝑇))) | 
| 104 | 1, 4, 103 | eqrelrdv 4759 | 
1
⊢ (𝜑 → (𝐺 ∘ 𝐹) = (𝑥 ∈ 𝐴 ↦ 𝑇)) |