| Step | Hyp | Ref
 | Expression | 
| 1 |   | basfn 12736 | 
. . . . 5
⊢ Base Fn
V | 
| 2 |   | vex 2766 | 
. . . . 5
⊢ 𝑔 ∈ V | 
| 3 |   | funfvex 5575 | 
. . . . . 6
⊢ ((Fun
Base ∧ 𝑔 ∈ dom
Base) → (Base‘𝑔)
∈ V) | 
| 4 | 3 | funfni 5358 | 
. . . . 5
⊢ ((Base Fn
V ∧ 𝑔 ∈ V) →
(Base‘𝑔) ∈
V) | 
| 5 | 1, 2, 4 | mp2an 426 | 
. . . 4
⊢
(Base‘𝑔)
∈ V | 
| 6 | 5 | a1i 9 | 
. . 3
⊢ (𝑔 = 𝑀 → (Base‘𝑔) ∈ V) | 
| 7 |   | fveq2 5558 | 
. . . 4
⊢ (𝑔 = 𝑀 → (Base‘𝑔) = (Base‘𝑀)) | 
| 8 |   | issgrp.b | 
. . . 4
⊢ 𝐵 = (Base‘𝑀) | 
| 9 | 7, 8 | eqtr4di 2247 | 
. . 3
⊢ (𝑔 = 𝑀 → (Base‘𝑔) = 𝐵) | 
| 10 |   | plusgslid 12790 | 
. . . . . . 7
⊢
(+g = Slot (+g‘ndx) ∧
(+g‘ndx) ∈ ℕ) | 
| 11 | 10 | slotex 12705 | 
. . . . . 6
⊢ (𝑔 ∈ V →
(+g‘𝑔)
∈ V) | 
| 12 | 11 | elv 2767 | 
. . . . 5
⊢
(+g‘𝑔) ∈ V | 
| 13 | 12 | a1i 9 | 
. . . 4
⊢ ((𝑔 = 𝑀 ∧ 𝑏 = 𝐵) → (+g‘𝑔) ∈ V) | 
| 14 |   | fveq2 5558 | 
. . . . . 6
⊢ (𝑔 = 𝑀 → (+g‘𝑔) = (+g‘𝑀)) | 
| 15 | 14 | adantr 276 | 
. . . . 5
⊢ ((𝑔 = 𝑀 ∧ 𝑏 = 𝐵) → (+g‘𝑔) = (+g‘𝑀)) | 
| 16 |   | issgrp.o | 
. . . . 5
⊢  ⚬ =
(+g‘𝑀) | 
| 17 | 15, 16 | eqtr4di 2247 | 
. . . 4
⊢ ((𝑔 = 𝑀 ∧ 𝑏 = 𝐵) → (+g‘𝑔) = ⚬ ) | 
| 18 |   | simplr 528 | 
. . . . 5
⊢ (((𝑔 = 𝑀 ∧ 𝑏 = 𝐵) ∧ 𝑜 = ⚬ ) → 𝑏 = 𝐵) | 
| 19 |   | id 19 | 
. . . . . . . . . 10
⊢ (𝑜 = ⚬ → 𝑜 = ⚬ ) | 
| 20 |   | oveq 5928 | 
. . . . . . . . . 10
⊢ (𝑜 = ⚬ → (𝑥𝑜𝑦) = (𝑥 ⚬ 𝑦)) | 
| 21 |   | eqidd 2197 | 
. . . . . . . . . 10
⊢ (𝑜 = ⚬ → 𝑧 = 𝑧) | 
| 22 | 19, 20, 21 | oveq123d 5943 | 
. . . . . . . . 9
⊢ (𝑜 = ⚬ → ((𝑥𝑜𝑦)𝑜𝑧) = ((𝑥 ⚬ 𝑦) ⚬ 𝑧)) | 
| 23 |   | eqidd 2197 | 
. . . . . . . . . 10
⊢ (𝑜 = ⚬ → 𝑥 = 𝑥) | 
| 24 |   | oveq 5928 | 
. . . . . . . . . 10
⊢ (𝑜 = ⚬ → (𝑦𝑜𝑧) = (𝑦 ⚬ 𝑧)) | 
| 25 | 19, 23, 24 | oveq123d 5943 | 
. . . . . . . . 9
⊢ (𝑜 = ⚬ → (𝑥𝑜(𝑦𝑜𝑧)) = (𝑥 ⚬ (𝑦 ⚬ 𝑧))) | 
| 26 | 22, 25 | eqeq12d 2211 | 
. . . . . . . 8
⊢ (𝑜 = ⚬ → (((𝑥𝑜𝑦)𝑜𝑧) = (𝑥𝑜(𝑦𝑜𝑧)) ↔ ((𝑥 ⚬ 𝑦) ⚬ 𝑧) = (𝑥 ⚬ (𝑦 ⚬ 𝑧)))) | 
| 27 | 26 | adantl 277 | 
. . . . . . 7
⊢ (((𝑔 = 𝑀 ∧ 𝑏 = 𝐵) ∧ 𝑜 = ⚬ ) → (((𝑥𝑜𝑦)𝑜𝑧) = (𝑥𝑜(𝑦𝑜𝑧)) ↔ ((𝑥 ⚬ 𝑦) ⚬ 𝑧) = (𝑥 ⚬ (𝑦 ⚬ 𝑧)))) | 
| 28 | 18, 27 | raleqbidv 2709 | 
. . . . . 6
⊢ (((𝑔 = 𝑀 ∧ 𝑏 = 𝐵) ∧ 𝑜 = ⚬ ) →
(∀𝑧 ∈ 𝑏 ((𝑥𝑜𝑦)𝑜𝑧) = (𝑥𝑜(𝑦𝑜𝑧)) ↔ ∀𝑧 ∈ 𝐵 ((𝑥 ⚬ 𝑦) ⚬ 𝑧) = (𝑥 ⚬ (𝑦 ⚬ 𝑧)))) | 
| 29 | 18, 28 | raleqbidv 2709 | 
. . . . 5
⊢ (((𝑔 = 𝑀 ∧ 𝑏 = 𝐵) ∧ 𝑜 = ⚬ ) →
(∀𝑦 ∈ 𝑏 ∀𝑧 ∈ 𝑏 ((𝑥𝑜𝑦)𝑜𝑧) = (𝑥𝑜(𝑦𝑜𝑧)) ↔ ∀𝑦 ∈ 𝐵 ∀𝑧 ∈ 𝐵 ((𝑥 ⚬ 𝑦) ⚬ 𝑧) = (𝑥 ⚬ (𝑦 ⚬ 𝑧)))) | 
| 30 | 18, 29 | raleqbidv 2709 | 
. . . 4
⊢ (((𝑔 = 𝑀 ∧ 𝑏 = 𝐵) ∧ 𝑜 = ⚬ ) →
(∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 ∀𝑧 ∈ 𝑏 ((𝑥𝑜𝑦)𝑜𝑧) = (𝑥𝑜(𝑦𝑜𝑧)) ↔ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 ∀𝑧 ∈ 𝐵 ((𝑥 ⚬ 𝑦) ⚬ 𝑧) = (𝑥 ⚬ (𝑦 ⚬ 𝑧)))) | 
| 31 | 13, 17, 30 | sbcied2 3027 | 
. . 3
⊢ ((𝑔 = 𝑀 ∧ 𝑏 = 𝐵) → ([(+g‘𝑔) / 𝑜]∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 ∀𝑧 ∈ 𝑏 ((𝑥𝑜𝑦)𝑜𝑧) = (𝑥𝑜(𝑦𝑜𝑧)) ↔ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 ∀𝑧 ∈ 𝐵 ((𝑥 ⚬ 𝑦) ⚬ 𝑧) = (𝑥 ⚬ (𝑦 ⚬ 𝑧)))) | 
| 32 | 6, 9, 31 | sbcied2 3027 | 
. 2
⊢ (𝑔 = 𝑀 → ([(Base‘𝑔) / 𝑏][(+g‘𝑔) / 𝑜]∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 ∀𝑧 ∈ 𝑏 ((𝑥𝑜𝑦)𝑜𝑧) = (𝑥𝑜(𝑦𝑜𝑧)) ↔ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 ∀𝑧 ∈ 𝐵 ((𝑥 ⚬ 𝑦) ⚬ 𝑧) = (𝑥 ⚬ (𝑦 ⚬ 𝑧)))) | 
| 33 |   | df-sgrp 13045 | 
. 2
⊢ Smgrp =
{𝑔 ∈ Mgm ∣
[(Base‘𝑔) /
𝑏][(+g‘𝑔) / 𝑜]∀𝑥 ∈ 𝑏 ∀𝑦 ∈ 𝑏 ∀𝑧 ∈ 𝑏 ((𝑥𝑜𝑦)𝑜𝑧) = (𝑥𝑜(𝑦𝑜𝑧))} | 
| 34 | 32, 33 | elrab2 2923 | 
1
⊢ (𝑀 ∈ Smgrp ↔ (𝑀 ∈ Mgm ∧ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 ∀𝑧 ∈ 𝐵 ((𝑥 ⚬ 𝑦) ⚬ 𝑧) = (𝑥 ⚬ (𝑦 ⚬ 𝑧)))) |