| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							polat.o | 
							⊢  ⊥   =  ( oc ‘ 𝐾 )  | 
						
						
							| 2 | 
							
								
							 | 
							polat.a | 
							⊢ 𝐴  =  ( Atoms ‘ 𝐾 )  | 
						
						
							| 3 | 
							
								
							 | 
							polat.m | 
							⊢ 𝑀  =  ( pmap ‘ 𝐾 )  | 
						
						
							| 4 | 
							
								
							 | 
							polat.p | 
							⊢ 𝑃  =  ( ⊥𝑃 ‘ 𝐾 )  | 
						
						
							| 5 | 
							
								
							 | 
							snssi | 
							⊢ ( 𝑄  ∈  𝐴  →  { 𝑄 }  ⊆  𝐴 )  | 
						
						
							| 6 | 
							
								1 2 3 4
							 | 
							polvalN | 
							⊢ ( ( 𝐾  ∈  OL  ∧  { 𝑄 }  ⊆  𝐴 )  →  ( 𝑃 ‘ { 𝑄 } )  =  ( 𝐴  ∩  ∩  𝑝  ∈  { 𝑄 } ( 𝑀 ‘ (  ⊥  ‘ 𝑝 ) ) ) )  | 
						
						
							| 7 | 
							
								5 6
							 | 
							sylan2 | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑄  ∈  𝐴 )  →  ( 𝑃 ‘ { 𝑄 } )  =  ( 𝐴  ∩  ∩  𝑝  ∈  { 𝑄 } ( 𝑀 ‘ (  ⊥  ‘ 𝑝 ) ) ) )  | 
						
						
							| 8 | 
							
								
							 | 
							2fveq3 | 
							⊢ ( 𝑝  =  𝑄  →  ( 𝑀 ‘ (  ⊥  ‘ 𝑝 ) )  =  ( 𝑀 ‘ (  ⊥  ‘ 𝑄 ) ) )  | 
						
						
							| 9 | 
							
								8
							 | 
							iinxsng | 
							⊢ ( 𝑄  ∈  𝐴  →  ∩  𝑝  ∈  { 𝑄 } ( 𝑀 ‘ (  ⊥  ‘ 𝑝 ) )  =  ( 𝑀 ‘ (  ⊥  ‘ 𝑄 ) ) )  | 
						
						
							| 10 | 
							
								9
							 | 
							adantl | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑄  ∈  𝐴 )  →  ∩  𝑝  ∈  { 𝑄 } ( 𝑀 ‘ (  ⊥  ‘ 𝑝 ) )  =  ( 𝑀 ‘ (  ⊥  ‘ 𝑄 ) ) )  | 
						
						
							| 11 | 
							
								10
							 | 
							ineq2d | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑄  ∈  𝐴 )  →  ( 𝐴  ∩  ∩  𝑝  ∈  { 𝑄 } ( 𝑀 ‘ (  ⊥  ‘ 𝑝 ) ) )  =  ( 𝐴  ∩  ( 𝑀 ‘ (  ⊥  ‘ 𝑄 ) ) ) )  | 
						
						
							| 12 | 
							
								
							 | 
							olop | 
							⊢ ( 𝐾  ∈  OL  →  𝐾  ∈  OP )  | 
						
						
							| 13 | 
							
								
							 | 
							eqid | 
							⊢ ( Base ‘ 𝐾 )  =  ( Base ‘ 𝐾 )  | 
						
						
							| 14 | 
							
								13 2
							 | 
							atbase | 
							⊢ ( 𝑄  ∈  𝐴  →  𝑄  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 15 | 
							
								13 1
							 | 
							opoccl | 
							⊢ ( ( 𝐾  ∈  OP  ∧  𝑄  ∈  ( Base ‘ 𝐾 ) )  →  (  ⊥  ‘ 𝑄 )  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 16 | 
							
								12 14 15
							 | 
							syl2an | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑄  ∈  𝐴 )  →  (  ⊥  ‘ 𝑄 )  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 17 | 
							
								13 2 3
							 | 
							pmapssat | 
							⊢ ( ( 𝐾  ∈  OL  ∧  (  ⊥  ‘ 𝑄 )  ∈  ( Base ‘ 𝐾 ) )  →  ( 𝑀 ‘ (  ⊥  ‘ 𝑄 ) )  ⊆  𝐴 )  | 
						
						
							| 18 | 
							
								16 17
							 | 
							syldan | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑄  ∈  𝐴 )  →  ( 𝑀 ‘ (  ⊥  ‘ 𝑄 ) )  ⊆  𝐴 )  | 
						
						
							| 19 | 
							
								
							 | 
							sseqin2 | 
							⊢ ( ( 𝑀 ‘ (  ⊥  ‘ 𝑄 ) )  ⊆  𝐴  ↔  ( 𝐴  ∩  ( 𝑀 ‘ (  ⊥  ‘ 𝑄 ) ) )  =  ( 𝑀 ‘ (  ⊥  ‘ 𝑄 ) ) )  | 
						
						
							| 20 | 
							
								18 19
							 | 
							sylib | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑄  ∈  𝐴 )  →  ( 𝐴  ∩  ( 𝑀 ‘ (  ⊥  ‘ 𝑄 ) ) )  =  ( 𝑀 ‘ (  ⊥  ‘ 𝑄 ) ) )  | 
						
						
							| 21 | 
							
								7 11 20
							 | 
							3eqtrd | 
							⊢ ( ( 𝐾  ∈  OL  ∧  𝑄  ∈  𝐴 )  →  ( 𝑃 ‘ { 𝑄 } )  =  ( 𝑀 ‘ (  ⊥  ‘ 𝑄 ) ) )  |