| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							ltrnel.l | 
							 |-  .<_ = ( le ` K )  | 
						
						
							| 2 | 
							
								
							 | 
							ltrnel.a | 
							 |-  A = ( Atoms ` K )  | 
						
						
							| 3 | 
							
								
							 | 
							ltrnel.h | 
							 |-  H = ( LHyp ` K )  | 
						
						
							| 4 | 
							
								
							 | 
							ltrnel.t | 
							 |-  T = ( ( LTrn ` K ) ` W )  | 
						
						
							| 5 | 
							
								
							 | 
							simp1 | 
							 |-  ( ( ( K e. HL /\ W e. H ) /\ ( F e. T /\ G e. T ) /\ P e. A ) -> ( K e. HL /\ W e. H ) )  | 
						
						
							| 6 | 
							
								
							 | 
							simp2r | 
							 |-  ( ( ( K e. HL /\ W e. H ) /\ ( F e. T /\ G e. T ) /\ P e. A ) -> G e. T )  | 
						
						
							| 7 | 
							
								
							 | 
							eqid | 
							 |-  ( Base ` K ) = ( Base ` K )  | 
						
						
							| 8 | 
							
								7 3 4
							 | 
							ltrn1o | 
							 |-  ( ( ( K e. HL /\ W e. H ) /\ G e. T ) -> G : ( Base ` K ) -1-1-onto-> ( Base ` K ) )  | 
						
						
							| 9 | 
							
								5 6 8
							 | 
							syl2anc | 
							 |-  ( ( ( K e. HL /\ W e. H ) /\ ( F e. T /\ G e. T ) /\ P e. A ) -> G : ( Base ` K ) -1-1-onto-> ( Base ` K ) )  | 
						
						
							| 10 | 
							
								
							 | 
							f1of | 
							 |-  ( G : ( Base ` K ) -1-1-onto-> ( Base ` K ) -> G : ( Base ` K ) --> ( Base ` K ) )  | 
						
						
							| 11 | 
							
								9 10
							 | 
							syl | 
							 |-  ( ( ( K e. HL /\ W e. H ) /\ ( F e. T /\ G e. T ) /\ P e. A ) -> G : ( Base ` K ) --> ( Base ` K ) )  | 
						
						
							| 12 | 
							
								7 2
							 | 
							atbase | 
							 |-  ( P e. A -> P e. ( Base ` K ) )  | 
						
						
							| 13 | 
							
								12
							 | 
							3ad2ant3 | 
							 |-  ( ( ( K e. HL /\ W e. H ) /\ ( F e. T /\ G e. T ) /\ P e. A ) -> P e. ( Base ` K ) )  | 
						
						
							| 14 | 
							
								
							 | 
							fvco3 | 
							 |-  ( ( G : ( Base ` K ) --> ( Base ` K ) /\ P e. ( Base ` K ) ) -> ( ( F o. G ) ` P ) = ( F ` ( G ` P ) ) )  | 
						
						
							| 15 | 
							
								11 13 14
							 | 
							syl2anc | 
							 |-  ( ( ( K e. HL /\ W e. H ) /\ ( F e. T /\ G e. T ) /\ P e. A ) -> ( ( F o. G ) ` P ) = ( F ` ( G ` P ) ) )  |