| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mclsval.d | ⊢ 𝐷  =  ( mDV ‘ 𝑇 ) | 
						
							| 2 |  | mclsval.e | ⊢ 𝐸  =  ( mEx ‘ 𝑇 ) | 
						
							| 3 |  | mclsval.c | ⊢ 𝐶  =  ( mCls ‘ 𝑇 ) | 
						
							| 4 |  | n0i | ⊢ ( 𝐴  ∈  ( 𝐾 𝐶 𝐵 )  →  ¬  ( 𝐾 𝐶 𝐵 )  =  ∅ ) | 
						
							| 5 |  | fvprc | ⊢ ( ¬  𝑇  ∈  V  →  ( mCls ‘ 𝑇 )  =  ∅ ) | 
						
							| 6 | 3 5 | eqtrid | ⊢ ( ¬  𝑇  ∈  V  →  𝐶  =  ∅ ) | 
						
							| 7 | 6 | oveqd | ⊢ ( ¬  𝑇  ∈  V  →  ( 𝐾 𝐶 𝐵 )  =  ( 𝐾 ∅ 𝐵 ) ) | 
						
							| 8 |  | 0ov | ⊢ ( 𝐾 ∅ 𝐵 )  =  ∅ | 
						
							| 9 | 7 8 | eqtrdi | ⊢ ( ¬  𝑇  ∈  V  →  ( 𝐾 𝐶 𝐵 )  =  ∅ ) | 
						
							| 10 | 4 9 | nsyl2 | ⊢ ( 𝐴  ∈  ( 𝐾 𝐶 𝐵 )  →  𝑇  ∈  V ) | 
						
							| 11 |  | fveq2 | ⊢ ( 𝑡  =  𝑇  →  ( mCls ‘ 𝑡 )  =  ( mCls ‘ 𝑇 ) ) | 
						
							| 12 | 11 3 | eqtr4di | ⊢ ( 𝑡  =  𝑇  →  ( mCls ‘ 𝑡 )  =  𝐶 ) | 
						
							| 13 | 12 | oveqd | ⊢ ( 𝑡  =  𝑇  →  ( 𝐾 ( mCls ‘ 𝑡 ) 𝐵 )  =  ( 𝐾 𝐶 𝐵 ) ) | 
						
							| 14 | 13 | eleq2d | ⊢ ( 𝑡  =  𝑇  →  ( 𝐴  ∈  ( 𝐾 ( mCls ‘ 𝑡 ) 𝐵 )  ↔  𝐴  ∈  ( 𝐾 𝐶 𝐵 ) ) ) | 
						
							| 15 |  | fvex | ⊢ ( mDV ‘ 𝑡 )  ∈  V | 
						
							| 16 | 15 | elpw2 | ⊢ ( 𝐾  ∈  𝒫  ( mDV ‘ 𝑡 )  ↔  𝐾  ⊆  ( mDV ‘ 𝑡 ) ) | 
						
							| 17 |  | fveq2 | ⊢ ( 𝑡  =  𝑇  →  ( mDV ‘ 𝑡 )  =  ( mDV ‘ 𝑇 ) ) | 
						
							| 18 | 17 1 | eqtr4di | ⊢ ( 𝑡  =  𝑇  →  ( mDV ‘ 𝑡 )  =  𝐷 ) | 
						
							| 19 | 18 | sseq2d | ⊢ ( 𝑡  =  𝑇  →  ( 𝐾  ⊆  ( mDV ‘ 𝑡 )  ↔  𝐾  ⊆  𝐷 ) ) | 
						
							| 20 | 16 19 | bitrid | ⊢ ( 𝑡  =  𝑇  →  ( 𝐾  ∈  𝒫  ( mDV ‘ 𝑡 )  ↔  𝐾  ⊆  𝐷 ) ) | 
						
							| 21 |  | fvex | ⊢ ( mEx ‘ 𝑡 )  ∈  V | 
						
							| 22 | 21 | elpw2 | ⊢ ( 𝐵  ∈  𝒫  ( mEx ‘ 𝑡 )  ↔  𝐵  ⊆  ( mEx ‘ 𝑡 ) ) | 
						
							| 23 |  | fveq2 | ⊢ ( 𝑡  =  𝑇  →  ( mEx ‘ 𝑡 )  =  ( mEx ‘ 𝑇 ) ) | 
						
							| 24 | 23 2 | eqtr4di | ⊢ ( 𝑡  =  𝑇  →  ( mEx ‘ 𝑡 )  =  𝐸 ) | 
						
							| 25 | 24 | sseq2d | ⊢ ( 𝑡  =  𝑇  →  ( 𝐵  ⊆  ( mEx ‘ 𝑡 )  ↔  𝐵  ⊆  𝐸 ) ) | 
						
							| 26 | 22 25 | bitrid | ⊢ ( 𝑡  =  𝑇  →  ( 𝐵  ∈  𝒫  ( mEx ‘ 𝑡 )  ↔  𝐵  ⊆  𝐸 ) ) | 
						
							| 27 | 20 26 | anbi12d | ⊢ ( 𝑡  =  𝑇  →  ( ( 𝐾  ∈  𝒫  ( mDV ‘ 𝑡 )  ∧  𝐵  ∈  𝒫  ( mEx ‘ 𝑡 ) )  ↔  ( 𝐾  ⊆  𝐷  ∧  𝐵  ⊆  𝐸 ) ) ) | 
						
							| 28 | 14 27 | imbi12d | ⊢ ( 𝑡  =  𝑇  →  ( ( 𝐴  ∈  ( 𝐾 ( mCls ‘ 𝑡 ) 𝐵 )  →  ( 𝐾  ∈  𝒫  ( mDV ‘ 𝑡 )  ∧  𝐵  ∈  𝒫  ( mEx ‘ 𝑡 ) ) )  ↔  ( 𝐴  ∈  ( 𝐾 𝐶 𝐵 )  →  ( 𝐾  ⊆  𝐷  ∧  𝐵  ⊆  𝐸 ) ) ) ) | 
						
							| 29 |  | vex | ⊢ 𝑡  ∈  V | 
						
							| 30 | 15 | pwex | ⊢ 𝒫  ( mDV ‘ 𝑡 )  ∈  V | 
						
							| 31 | 21 | pwex | ⊢ 𝒫  ( mEx ‘ 𝑡 )  ∈  V | 
						
							| 32 | 30 31 | mpoex | ⊢ ( 𝑑  ∈  𝒫  ( mDV ‘ 𝑡 ) ,  ℎ  ∈  𝒫  ( mEx ‘ 𝑡 )  ↦  ∩  { 𝑐  ∣  ( ( ℎ  ∪  ran  ( mVH ‘ 𝑡 ) )  ⊆  𝑐  ∧  ∀ 𝑚 ∀ 𝑜 ∀ 𝑝 ( 〈 𝑚 ,  𝑜 ,  𝑝 〉  ∈  ( mAx ‘ 𝑡 )  →  ∀ 𝑠  ∈  ran  ( mSubst ‘ 𝑡 ) ( ( ( 𝑠  “  ( 𝑜  ∪  ran  ( mVH ‘ 𝑡 ) ) )  ⊆  𝑐  ∧  ∀ 𝑥 ∀ 𝑦 ( 𝑥 𝑚 𝑦  →  ( ( ( mVars ‘ 𝑡 ) ‘ ( 𝑠 ‘ ( ( mVH ‘ 𝑡 ) ‘ 𝑥 ) ) )  ×  ( ( mVars ‘ 𝑡 ) ‘ ( 𝑠 ‘ ( ( mVH ‘ 𝑡 ) ‘ 𝑦 ) ) ) )  ⊆  𝑑 ) )  →  ( 𝑠 ‘ 𝑝 )  ∈  𝑐 ) ) ) } )  ∈  V | 
						
							| 33 |  | df-mcls | ⊢ mCls  =  ( 𝑡  ∈  V  ↦  ( 𝑑  ∈  𝒫  ( mDV ‘ 𝑡 ) ,  ℎ  ∈  𝒫  ( mEx ‘ 𝑡 )  ↦  ∩  { 𝑐  ∣  ( ( ℎ  ∪  ran  ( mVH ‘ 𝑡 ) )  ⊆  𝑐  ∧  ∀ 𝑚 ∀ 𝑜 ∀ 𝑝 ( 〈 𝑚 ,  𝑜 ,  𝑝 〉  ∈  ( mAx ‘ 𝑡 )  →  ∀ 𝑠  ∈  ran  ( mSubst ‘ 𝑡 ) ( ( ( 𝑠  “  ( 𝑜  ∪  ran  ( mVH ‘ 𝑡 ) ) )  ⊆  𝑐  ∧  ∀ 𝑥 ∀ 𝑦 ( 𝑥 𝑚 𝑦  →  ( ( ( mVars ‘ 𝑡 ) ‘ ( 𝑠 ‘ ( ( mVH ‘ 𝑡 ) ‘ 𝑥 ) ) )  ×  ( ( mVars ‘ 𝑡 ) ‘ ( 𝑠 ‘ ( ( mVH ‘ 𝑡 ) ‘ 𝑦 ) ) ) )  ⊆  𝑑 ) )  →  ( 𝑠 ‘ 𝑝 )  ∈  𝑐 ) ) ) } ) ) | 
						
							| 34 | 33 | fvmpt2 | ⊢ ( ( 𝑡  ∈  V  ∧  ( 𝑑  ∈  𝒫  ( mDV ‘ 𝑡 ) ,  ℎ  ∈  𝒫  ( mEx ‘ 𝑡 )  ↦  ∩  { 𝑐  ∣  ( ( ℎ  ∪  ran  ( mVH ‘ 𝑡 ) )  ⊆  𝑐  ∧  ∀ 𝑚 ∀ 𝑜 ∀ 𝑝 ( 〈 𝑚 ,  𝑜 ,  𝑝 〉  ∈  ( mAx ‘ 𝑡 )  →  ∀ 𝑠  ∈  ran  ( mSubst ‘ 𝑡 ) ( ( ( 𝑠  “  ( 𝑜  ∪  ran  ( mVH ‘ 𝑡 ) ) )  ⊆  𝑐  ∧  ∀ 𝑥 ∀ 𝑦 ( 𝑥 𝑚 𝑦  →  ( ( ( mVars ‘ 𝑡 ) ‘ ( 𝑠 ‘ ( ( mVH ‘ 𝑡 ) ‘ 𝑥 ) ) )  ×  ( ( mVars ‘ 𝑡 ) ‘ ( 𝑠 ‘ ( ( mVH ‘ 𝑡 ) ‘ 𝑦 ) ) ) )  ⊆  𝑑 ) )  →  ( 𝑠 ‘ 𝑝 )  ∈  𝑐 ) ) ) } )  ∈  V )  →  ( mCls ‘ 𝑡 )  =  ( 𝑑  ∈  𝒫  ( mDV ‘ 𝑡 ) ,  ℎ  ∈  𝒫  ( mEx ‘ 𝑡 )  ↦  ∩  { 𝑐  ∣  ( ( ℎ  ∪  ran  ( mVH ‘ 𝑡 ) )  ⊆  𝑐  ∧  ∀ 𝑚 ∀ 𝑜 ∀ 𝑝 ( 〈 𝑚 ,  𝑜 ,  𝑝 〉  ∈  ( mAx ‘ 𝑡 )  →  ∀ 𝑠  ∈  ran  ( mSubst ‘ 𝑡 ) ( ( ( 𝑠  “  ( 𝑜  ∪  ran  ( mVH ‘ 𝑡 ) ) )  ⊆  𝑐  ∧  ∀ 𝑥 ∀ 𝑦 ( 𝑥 𝑚 𝑦  →  ( ( ( mVars ‘ 𝑡 ) ‘ ( 𝑠 ‘ ( ( mVH ‘ 𝑡 ) ‘ 𝑥 ) ) )  ×  ( ( mVars ‘ 𝑡 ) ‘ ( 𝑠 ‘ ( ( mVH ‘ 𝑡 ) ‘ 𝑦 ) ) ) )  ⊆  𝑑 ) )  →  ( 𝑠 ‘ 𝑝 )  ∈  𝑐 ) ) ) } ) ) | 
						
							| 35 | 29 32 34 | mp2an | ⊢ ( mCls ‘ 𝑡 )  =  ( 𝑑  ∈  𝒫  ( mDV ‘ 𝑡 ) ,  ℎ  ∈  𝒫  ( mEx ‘ 𝑡 )  ↦  ∩  { 𝑐  ∣  ( ( ℎ  ∪  ran  ( mVH ‘ 𝑡 ) )  ⊆  𝑐  ∧  ∀ 𝑚 ∀ 𝑜 ∀ 𝑝 ( 〈 𝑚 ,  𝑜 ,  𝑝 〉  ∈  ( mAx ‘ 𝑡 )  →  ∀ 𝑠  ∈  ran  ( mSubst ‘ 𝑡 ) ( ( ( 𝑠  “  ( 𝑜  ∪  ran  ( mVH ‘ 𝑡 ) ) )  ⊆  𝑐  ∧  ∀ 𝑥 ∀ 𝑦 ( 𝑥 𝑚 𝑦  →  ( ( ( mVars ‘ 𝑡 ) ‘ ( 𝑠 ‘ ( ( mVH ‘ 𝑡 ) ‘ 𝑥 ) ) )  ×  ( ( mVars ‘ 𝑡 ) ‘ ( 𝑠 ‘ ( ( mVH ‘ 𝑡 ) ‘ 𝑦 ) ) ) )  ⊆  𝑑 ) )  →  ( 𝑠 ‘ 𝑝 )  ∈  𝑐 ) ) ) } ) | 
						
							| 36 | 35 | elmpocl | ⊢ ( 𝐴  ∈  ( 𝐾 ( mCls ‘ 𝑡 ) 𝐵 )  →  ( 𝐾  ∈  𝒫  ( mDV ‘ 𝑡 )  ∧  𝐵  ∈  𝒫  ( mEx ‘ 𝑡 ) ) ) | 
						
							| 37 | 28 36 | vtoclg | ⊢ ( 𝑇  ∈  V  →  ( 𝐴  ∈  ( 𝐾 𝐶 𝐵 )  →  ( 𝐾  ⊆  𝐷  ∧  𝐵  ⊆  𝐸 ) ) ) | 
						
							| 38 | 10 37 | mpcom | ⊢ ( 𝐴  ∈  ( 𝐾 𝐶 𝐵 )  →  ( 𝐾  ⊆  𝐷  ∧  𝐵  ⊆  𝐸 ) ) | 
						
							| 39 | 38 | simpld | ⊢ ( 𝐴  ∈  ( 𝐾 𝐶 𝐵 )  →  𝐾  ⊆  𝐷 ) | 
						
							| 40 | 38 | simprd | ⊢ ( 𝐴  ∈  ( 𝐾 𝐶 𝐵 )  →  𝐵  ⊆  𝐸 ) | 
						
							| 41 | 10 39 40 | 3jca | ⊢ ( 𝐴  ∈  ( 𝐾 𝐶 𝐵 )  →  ( 𝑇  ∈  V  ∧  𝐾  ⊆  𝐷  ∧  𝐵  ⊆  𝐸 ) ) |