| Step | Hyp | Ref | Expression | 
						
							| 1 |  | xpsval.t |  | 
						
							| 2 |  | xpsval.x |  | 
						
							| 3 |  | xpsval.y |  | 
						
							| 4 |  | xpsval.1 |  | 
						
							| 5 |  | xpsval.2 |  | 
						
							| 6 |  | xpsval.f |  | 
						
							| 7 |  | xpsval.k |  | 
						
							| 8 |  | xpsval.u |  | 
						
							| 9 |  | eqid |  | 
						
							| 10 | 7 | fvexi |  | 
						
							| 11 | 10 | a1i |  | 
						
							| 12 |  | 2on |  | 
						
							| 13 | 12 | a1i |  | 
						
							| 14 |  | fnpr2o |  | 
						
							| 15 | 4 5 14 | syl2anc |  | 
						
							| 16 | 8 9 11 13 15 | prdsbas2 |  | 
						
							| 17 |  | fvprif |  | 
						
							| 18 | 17 | 3expia |  | 
						
							| 19 | 4 5 18 | syl2anc |  | 
						
							| 20 | 19 | imp |  | 
						
							| 21 | 20 | fveq2d |  | 
						
							| 22 |  | ifeq12 |  | 
						
							| 23 | 2 3 22 | mp2an |  | 
						
							| 24 |  | fvif |  | 
						
							| 25 | 23 24 | eqtr4i |  | 
						
							| 26 | 21 25 | eqtr4di |  | 
						
							| 27 | 26 | ixpeq2dva |  | 
						
							| 28 | 6 | xpsfrn |  | 
						
							| 29 | 27 28 | eqtr4di |  | 
						
							| 30 | 16 29 | eqtr2d |  |