| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | ovres 7600 | . . . . 5
⊢ ((𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑍) → (𝑥( ⊕ ↾ (𝑋 × 𝑍))𝑦) = (𝑥 ⊕ 𝑦)) | 
| 2 | 1 | adantl 481 | . . . 4
⊢ ((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ( ⊕ ↾ (𝑋 × 𝑍)) ∈ (𝐺 GrpAct 𝑍)) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑍)) → (𝑥( ⊕ ↾ (𝑋 × 𝑍))𝑦) = (𝑥 ⊕ 𝑦)) | 
| 3 |  | gass.1 | . . . . . . 7
⊢ 𝑋 = (Base‘𝐺) | 
| 4 | 3 | gaf 19314 | . . . . . 6
⊢ (( ⊕
↾ (𝑋 × 𝑍)) ∈ (𝐺 GrpAct 𝑍) → ( ⊕ ↾ (𝑋 × 𝑍)):(𝑋 × 𝑍)⟶𝑍) | 
| 5 | 4 | adantl 481 | . . . . 5
⊢ ((( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ( ⊕ ↾ (𝑋 × 𝑍)) ∈ (𝐺 GrpAct 𝑍)) → ( ⊕ ↾ (𝑋 × 𝑍)):(𝑋 × 𝑍)⟶𝑍) | 
| 6 | 5 | fovcdmda 7605 | . . . 4
⊢ ((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ( ⊕ ↾ (𝑋 × 𝑍)) ∈ (𝐺 GrpAct 𝑍)) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑍)) → (𝑥( ⊕ ↾ (𝑋 × 𝑍))𝑦) ∈ 𝑍) | 
| 7 | 2, 6 | eqeltrrd 2841 | . . 3
⊢ ((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ( ⊕ ↾ (𝑋 × 𝑍)) ∈ (𝐺 GrpAct 𝑍)) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑍)) → (𝑥 ⊕ 𝑦) ∈ 𝑍) | 
| 8 | 7 | ralrimivva 3201 | . 2
⊢ ((( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ( ⊕ ↾ (𝑋 × 𝑍)) ∈ (𝐺 GrpAct 𝑍)) → ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) | 
| 9 |  | gagrp 19311 | . . . . 5
⊢ ( ⊕ ∈
(𝐺 GrpAct 𝑌) → 𝐺 ∈ Grp) | 
| 10 | 9 | ad2antrr 726 | . . . 4
⊢ ((( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) → 𝐺 ∈ Grp) | 
| 11 |  | gaset 19312 | . . . . . . 7
⊢ ( ⊕ ∈
(𝐺 GrpAct 𝑌) → 𝑌 ∈ V) | 
| 12 | 11 | adantr 480 | . . . . . 6
⊢ (( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) → 𝑌 ∈ V) | 
| 13 |  | simpr 484 | . . . . . 6
⊢ (( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) → 𝑍 ⊆ 𝑌) | 
| 14 | 12, 13 | ssexd 5323 | . . . . 5
⊢ (( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) → 𝑍 ∈ V) | 
| 15 | 14 | adantr 480 | . . . 4
⊢ ((( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) → 𝑍 ∈ V) | 
| 16 | 10, 15 | jca 511 | . . 3
⊢ ((( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) → (𝐺 ∈ Grp ∧ 𝑍 ∈ V)) | 
| 17 | 3 | gaf 19314 | . . . . . . . 8
⊢ ( ⊕ ∈
(𝐺 GrpAct 𝑌) → ⊕ :(𝑋 × 𝑌)⟶𝑌) | 
| 18 | 17 | ad2antrr 726 | . . . . . . 7
⊢ ((( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) → ⊕ :(𝑋 × 𝑌)⟶𝑌) | 
| 19 | 18 | ffnd 6736 | . . . . . 6
⊢ ((( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) → ⊕ Fn (𝑋 × 𝑌)) | 
| 20 |  | simplr 768 | . . . . . . 7
⊢ ((( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) → 𝑍 ⊆ 𝑌) | 
| 21 |  | xpss2 5704 | . . . . . . 7
⊢ (𝑍 ⊆ 𝑌 → (𝑋 × 𝑍) ⊆ (𝑋 × 𝑌)) | 
| 22 | 20, 21 | syl 17 | . . . . . 6
⊢ ((( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) → (𝑋 × 𝑍) ⊆ (𝑋 × 𝑌)) | 
| 23 |  | fnssres 6690 | . . . . . 6
⊢ (( ⊕ Fn
(𝑋 × 𝑌) ∧ (𝑋 × 𝑍) ⊆ (𝑋 × 𝑌)) → ( ⊕ ↾ (𝑋 × 𝑍)) Fn (𝑋 × 𝑍)) | 
| 24 | 19, 22, 23 | syl2anc 584 | . . . . 5
⊢ ((( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) → ( ⊕ ↾ (𝑋 × 𝑍)) Fn (𝑋 × 𝑍)) | 
| 25 |  | simpr 484 | . . . . . 6
⊢ ((( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) → ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) | 
| 26 | 1 | eleq1d 2825 | . . . . . . . 8
⊢ ((𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑍) → ((𝑥( ⊕ ↾ (𝑋 × 𝑍))𝑦) ∈ 𝑍 ↔ (𝑥 ⊕ 𝑦) ∈ 𝑍)) | 
| 27 | 26 | ralbidva 3175 | . . . . . . 7
⊢ (𝑥 ∈ 𝑋 → (∀𝑦 ∈ 𝑍 (𝑥( ⊕ ↾ (𝑋 × 𝑍))𝑦) ∈ 𝑍 ↔ ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍)) | 
| 28 | 27 | ralbiia 3090 | . . . . . 6
⊢
(∀𝑥 ∈
𝑋 ∀𝑦 ∈ 𝑍 (𝑥( ⊕ ↾ (𝑋 × 𝑍))𝑦) ∈ 𝑍 ↔ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) | 
| 29 | 25, 28 | sylibr 234 | . . . . 5
⊢ ((( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) → ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥( ⊕ ↾ (𝑋 × 𝑍))𝑦) ∈ 𝑍) | 
| 30 |  | ffnov 7560 | . . . . 5
⊢ (( ⊕
↾ (𝑋 × 𝑍)):(𝑋 × 𝑍)⟶𝑍 ↔ (( ⊕ ↾ (𝑋 × 𝑍)) Fn (𝑋 × 𝑍) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥( ⊕ ↾ (𝑋 × 𝑍))𝑦) ∈ 𝑍)) | 
| 31 | 24, 29, 30 | sylanbrc 583 | . . . 4
⊢ ((( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) → ( ⊕ ↾ (𝑋 × 𝑍)):(𝑋 × 𝑍)⟶𝑍) | 
| 32 |  | eqid 2736 | . . . . . . . . . 10
⊢
(0g‘𝐺) = (0g‘𝐺) | 
| 33 | 3, 32 | grpidcl 18984 | . . . . . . . . 9
⊢ (𝐺 ∈ Grp →
(0g‘𝐺)
∈ 𝑋) | 
| 34 | 10, 33 | syl 17 | . . . . . . . 8
⊢ ((( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) → (0g‘𝐺) ∈ 𝑋) | 
| 35 |  | ovres 7600 | . . . . . . . 8
⊢
(((0g‘𝐺) ∈ 𝑋 ∧ 𝑧 ∈ 𝑍) → ((0g‘𝐺)( ⊕ ↾ (𝑋 × 𝑍))𝑧) = ((0g‘𝐺) ⊕ 𝑧)) | 
| 36 | 34, 35 | sylan 580 | . . . . . . 7
⊢ ((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) → ((0g‘𝐺)( ⊕ ↾ (𝑋 × 𝑍))𝑧) = ((0g‘𝐺) ⊕ 𝑧)) | 
| 37 |  | simpll 766 | . . . . . . . 8
⊢ ((( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) → ⊕ ∈ (𝐺 GrpAct 𝑌)) | 
| 38 | 20 | sselda 3982 | . . . . . . . 8
⊢ ((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) → 𝑧 ∈ 𝑌) | 
| 39 | 32 | gagrpid 19313 | . . . . . . . 8
⊢ (( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑧 ∈ 𝑌) → ((0g‘𝐺) ⊕ 𝑧) = 𝑧) | 
| 40 | 37, 38, 39 | syl2an2r 685 | . . . . . . 7
⊢ ((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) → ((0g‘𝐺) ⊕ 𝑧) = 𝑧) | 
| 41 | 36, 40 | eqtrd 2776 | . . . . . 6
⊢ ((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) → ((0g‘𝐺)( ⊕ ↾ (𝑋 × 𝑍))𝑧) = 𝑧) | 
| 42 | 37 | ad2antrr 726 | . . . . . . . . . 10
⊢ (((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → ⊕ ∈ (𝐺 GrpAct 𝑌)) | 
| 43 |  | simprl 770 | . . . . . . . . . 10
⊢ (((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → 𝑢 ∈ 𝑋) | 
| 44 |  | simprr 772 | . . . . . . . . . 10
⊢ (((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → 𝑣 ∈ 𝑋) | 
| 45 | 38 | adantr 480 | . . . . . . . . . 10
⊢ (((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → 𝑧 ∈ 𝑌) | 
| 46 |  | eqid 2736 | . . . . . . . . . . 11
⊢
(+g‘𝐺) = (+g‘𝐺) | 
| 47 | 3, 46 | gaass 19316 | . . . . . . . . . 10
⊢ (( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋 ∧ 𝑧 ∈ 𝑌)) → ((𝑢(+g‘𝐺)𝑣) ⊕ 𝑧) = (𝑢 ⊕ (𝑣 ⊕ 𝑧))) | 
| 48 | 42, 43, 44, 45, 47 | syl13anc 1373 | . . . . . . . . 9
⊢ (((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → ((𝑢(+g‘𝐺)𝑣) ⊕ 𝑧) = (𝑢 ⊕ (𝑣 ⊕ 𝑧))) | 
| 49 |  | simplr 768 | . . . . . . . . . . 11
⊢ (((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → 𝑧 ∈ 𝑍) | 
| 50 |  | simpllr 775 | . . . . . . . . . . 11
⊢ (((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) | 
| 51 |  | ovrspc2v 7458 | . . . . . . . . . . 11
⊢ (((𝑣 ∈ 𝑋 ∧ 𝑧 ∈ 𝑍) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) → (𝑣 ⊕ 𝑧) ∈ 𝑍) | 
| 52 | 44, 49, 50, 51 | syl21anc 837 | . . . . . . . . . 10
⊢ (((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → (𝑣 ⊕ 𝑧) ∈ 𝑍) | 
| 53 |  | ovres 7600 | . . . . . . . . . 10
⊢ ((𝑢 ∈ 𝑋 ∧ (𝑣 ⊕ 𝑧) ∈ 𝑍) → (𝑢( ⊕ ↾ (𝑋 × 𝑍))(𝑣 ⊕ 𝑧)) = (𝑢 ⊕ (𝑣 ⊕ 𝑧))) | 
| 54 | 43, 52, 53 | syl2anc 584 | . . . . . . . . 9
⊢ (((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → (𝑢( ⊕ ↾ (𝑋 × 𝑍))(𝑣 ⊕ 𝑧)) = (𝑢 ⊕ (𝑣 ⊕ 𝑧))) | 
| 55 | 48, 54 | eqtr4d 2779 | . . . . . . . 8
⊢ (((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → ((𝑢(+g‘𝐺)𝑣) ⊕ 𝑧) = (𝑢( ⊕ ↾ (𝑋 × 𝑍))(𝑣 ⊕ 𝑧))) | 
| 56 | 10 | ad2antrr 726 | . . . . . . . . . 10
⊢ (((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → 𝐺 ∈ Grp) | 
| 57 | 3, 46 | grpcl 18960 | . . . . . . . . . 10
⊢ ((𝐺 ∈ Grp ∧ 𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋) → (𝑢(+g‘𝐺)𝑣) ∈ 𝑋) | 
| 58 | 56, 43, 44, 57 | syl3anc 1372 | . . . . . . . . 9
⊢ (((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → (𝑢(+g‘𝐺)𝑣) ∈ 𝑋) | 
| 59 |  | ovres 7600 | . . . . . . . . 9
⊢ (((𝑢(+g‘𝐺)𝑣) ∈ 𝑋 ∧ 𝑧 ∈ 𝑍) → ((𝑢(+g‘𝐺)𝑣)( ⊕ ↾ (𝑋 × 𝑍))𝑧) = ((𝑢(+g‘𝐺)𝑣) ⊕ 𝑧)) | 
| 60 | 58, 49, 59 | syl2anc 584 | . . . . . . . 8
⊢ (((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → ((𝑢(+g‘𝐺)𝑣)( ⊕ ↾ (𝑋 × 𝑍))𝑧) = ((𝑢(+g‘𝐺)𝑣) ⊕ 𝑧)) | 
| 61 |  | ovres 7600 | . . . . . . . . . 10
⊢ ((𝑣 ∈ 𝑋 ∧ 𝑧 ∈ 𝑍) → (𝑣( ⊕ ↾ (𝑋 × 𝑍))𝑧) = (𝑣 ⊕ 𝑧)) | 
| 62 | 44, 49, 61 | syl2anc 584 | . . . . . . . . 9
⊢ (((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → (𝑣( ⊕ ↾ (𝑋 × 𝑍))𝑧) = (𝑣 ⊕ 𝑧)) | 
| 63 | 62 | oveq2d 7448 | . . . . . . . 8
⊢ (((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → (𝑢( ⊕ ↾ (𝑋 × 𝑍))(𝑣( ⊕ ↾ (𝑋 × 𝑍))𝑧)) = (𝑢( ⊕ ↾ (𝑋 × 𝑍))(𝑣 ⊕ 𝑧))) | 
| 64 | 55, 60, 63 | 3eqtr4d 2786 | . . . . . . 7
⊢ (((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → ((𝑢(+g‘𝐺)𝑣)( ⊕ ↾ (𝑋 × 𝑍))𝑧) = (𝑢( ⊕ ↾ (𝑋 × 𝑍))(𝑣( ⊕ ↾ (𝑋 × 𝑍))𝑧))) | 
| 65 | 64 | ralrimivva 3201 | . . . . . 6
⊢ ((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) → ∀𝑢 ∈ 𝑋 ∀𝑣 ∈ 𝑋 ((𝑢(+g‘𝐺)𝑣)( ⊕ ↾ (𝑋 × 𝑍))𝑧) = (𝑢( ⊕ ↾ (𝑋 × 𝑍))(𝑣( ⊕ ↾ (𝑋 × 𝑍))𝑧))) | 
| 66 | 41, 65 | jca 511 | . . . . 5
⊢ ((((
⊕
∈ (𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) ∧ 𝑧 ∈ 𝑍) → (((0g‘𝐺)( ⊕ ↾ (𝑋 × 𝑍))𝑧) = 𝑧 ∧ ∀𝑢 ∈ 𝑋 ∀𝑣 ∈ 𝑋 ((𝑢(+g‘𝐺)𝑣)( ⊕ ↾ (𝑋 × 𝑍))𝑧) = (𝑢( ⊕ ↾ (𝑋 × 𝑍))(𝑣( ⊕ ↾ (𝑋 × 𝑍))𝑧)))) | 
| 67 | 66 | ralrimiva 3145 | . . . 4
⊢ ((( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) → ∀𝑧 ∈ 𝑍 (((0g‘𝐺)( ⊕ ↾ (𝑋 × 𝑍))𝑧) = 𝑧 ∧ ∀𝑢 ∈ 𝑋 ∀𝑣 ∈ 𝑋 ((𝑢(+g‘𝐺)𝑣)( ⊕ ↾ (𝑋 × 𝑍))𝑧) = (𝑢( ⊕ ↾ (𝑋 × 𝑍))(𝑣( ⊕ ↾ (𝑋 × 𝑍))𝑧)))) | 
| 68 | 31, 67 | jca 511 | . . 3
⊢ ((( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) → (( ⊕ ↾ (𝑋 × 𝑍)):(𝑋 × 𝑍)⟶𝑍 ∧ ∀𝑧 ∈ 𝑍 (((0g‘𝐺)( ⊕ ↾ (𝑋 × 𝑍))𝑧) = 𝑧 ∧ ∀𝑢 ∈ 𝑋 ∀𝑣 ∈ 𝑋 ((𝑢(+g‘𝐺)𝑣)( ⊕ ↾ (𝑋 × 𝑍))𝑧) = (𝑢( ⊕ ↾ (𝑋 × 𝑍))(𝑣( ⊕ ↾ (𝑋 × 𝑍))𝑧))))) | 
| 69 | 3, 46, 32 | isga 19310 | . . 3
⊢ (( ⊕
↾ (𝑋 × 𝑍)) ∈ (𝐺 GrpAct 𝑍) ↔ ((𝐺 ∈ Grp ∧ 𝑍 ∈ V) ∧ (( ⊕ ↾ (𝑋 × 𝑍)):(𝑋 × 𝑍)⟶𝑍 ∧ ∀𝑧 ∈ 𝑍 (((0g‘𝐺)( ⊕ ↾ (𝑋 × 𝑍))𝑧) = 𝑧 ∧ ∀𝑢 ∈ 𝑋 ∀𝑣 ∈ 𝑋 ((𝑢(+g‘𝐺)𝑣)( ⊕ ↾ (𝑋 × 𝑍))𝑧) = (𝑢( ⊕ ↾ (𝑋 × 𝑍))(𝑣( ⊕ ↾ (𝑋 × 𝑍))𝑧)))))) | 
| 70 | 16, 68, 69 | sylanbrc 583 | . 2
⊢ ((( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) ∧ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍) → ( ⊕ ↾ (𝑋 × 𝑍)) ∈ (𝐺 GrpAct 𝑍)) | 
| 71 | 8, 70 | impbida 800 | 1
⊢ (( ⊕ ∈
(𝐺 GrpAct 𝑌) ∧ 𝑍 ⊆ 𝑌) → (( ⊕ ↾ (𝑋 × 𝑍)) ∈ (𝐺 GrpAct 𝑍) ↔ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑍 (𝑥 ⊕ 𝑦) ∈ 𝑍)) |