| Step | Hyp | Ref | Expression | 
						
							| 1 |  | efnnfsumcl.1 |  | 
						
							| 2 |  | efnnfsumcl.2 |  | 
						
							| 3 |  | efnnfsumcl.3 |  | 
						
							| 4 |  | ssrab2 |  | 
						
							| 5 |  | ax-resscn |  | 
						
							| 6 | 4 5 | sstri |  | 
						
							| 7 | 6 | a1i |  | 
						
							| 8 |  | fveq2 |  | 
						
							| 9 | 8 | eleq1d |  | 
						
							| 10 | 9 | elrab |  | 
						
							| 11 |  | fveq2 |  | 
						
							| 12 | 11 | eleq1d |  | 
						
							| 13 | 12 | elrab |  | 
						
							| 14 |  | fveq2 |  | 
						
							| 15 | 14 | eleq1d |  | 
						
							| 16 |  | simpll |  | 
						
							| 17 |  | simprl |  | 
						
							| 18 | 16 17 | readdcld |  | 
						
							| 19 | 16 | recnd |  | 
						
							| 20 | 17 | recnd |  | 
						
							| 21 |  | efadd |  | 
						
							| 22 | 19 20 21 | syl2anc |  | 
						
							| 23 |  | nnmulcl |  | 
						
							| 24 | 23 | ad2ant2l |  | 
						
							| 25 | 22 24 | eqeltrd |  | 
						
							| 26 | 15 18 25 | elrabd |  | 
						
							| 27 | 10 13 26 | syl2anb |  | 
						
							| 28 | 27 | adantl |  | 
						
							| 29 |  | fveq2 |  | 
						
							| 30 | 29 | eleq1d |  | 
						
							| 31 | 30 2 3 | elrabd |  | 
						
							| 32 |  | 0re |  | 
						
							| 33 |  | 1nn |  | 
						
							| 34 |  | fveq2 |  | 
						
							| 35 |  | ef0 |  | 
						
							| 36 | 34 35 | eqtrdi |  | 
						
							| 37 | 36 | eleq1d |  | 
						
							| 38 | 37 | elrab |  | 
						
							| 39 | 32 33 38 | mpbir2an |  | 
						
							| 40 | 39 | a1i |  | 
						
							| 41 | 7 28 1 31 40 | fsumcllem |  | 
						
							| 42 |  | fveq2 |  | 
						
							| 43 | 42 | eleq1d |  | 
						
							| 44 | 43 | elrab |  | 
						
							| 45 | 44 | simprbi |  | 
						
							| 46 | 41 45 | syl |  |