| Step | Hyp | Ref | Expression | 
						
							| 1 |  | fveecn |  | 
						
							| 2 |  | subid |  | 
						
							| 3 | 2 | sq0id |  | 
						
							| 4 | 1 3 | syl |  | 
						
							| 5 | 4 | sumeq2dv |  | 
						
							| 6 |  | fzfid |  | 
						
							| 7 |  | sumz |  | 
						
							| 8 | 7 | olcs |  | 
						
							| 9 | 6 8 | syl |  | 
						
							| 10 | 5 9 | eqtrd |  | 
						
							| 11 | 10 | 3ad2ant3 |  | 
						
							| 12 | 11 | eqeq2d |  | 
						
							| 13 |  | fzfid |  | 
						
							| 14 |  | fveere |  | 
						
							| 15 | 14 | adantlr |  | 
						
							| 16 |  | fveere |  | 
						
							| 17 | 16 | adantll |  | 
						
							| 18 | 15 17 | resubcld |  | 
						
							| 19 | 18 | resqcld |  | 
						
							| 20 | 18 | sqge0d |  | 
						
							| 21 | 13 19 20 | fsum00 |  | 
						
							| 22 |  | fveecn |  | 
						
							| 23 |  | fveecn |  | 
						
							| 24 |  | subcl |  | 
						
							| 25 |  | sqeq0 |  | 
						
							| 26 | 24 25 | syl |  | 
						
							| 27 |  | subeq0 |  | 
						
							| 28 | 26 27 | bitrd |  | 
						
							| 29 | 22 23 28 | syl2an |  | 
						
							| 30 | 29 | anandirs |  | 
						
							| 31 | 30 | ralbidva |  | 
						
							| 32 | 21 31 | bitrd |  | 
						
							| 33 | 32 | 3adant3 |  | 
						
							| 34 | 12 33 | bitrd |  | 
						
							| 35 |  | simp1 |  | 
						
							| 36 |  | simp2 |  | 
						
							| 37 |  | simp3 |  | 
						
							| 38 |  | brcgr |  | 
						
							| 39 | 35 36 37 37 38 | syl22anc |  | 
						
							| 40 |  | eqeefv |  | 
						
							| 41 | 40 | 3adant3 |  | 
						
							| 42 | 34 39 41 | 3bitr4d |  | 
						
							| 43 | 42 | biimpd |  | 
						
							| 44 | 43 | adantl |  |