| Step | Hyp | Ref | Expression | 
						
							| 1 |  | fzfid |  |-  ( ( A e. RR /\ B e. RR /\ A <_ B ) -> ( 1 ... ( |_ ` B ) ) e. Fin ) | 
						
							| 2 |  | elfznn |  |-  ( n e. ( 1 ... ( |_ ` B ) ) -> n e. NN ) | 
						
							| 3 | 2 | adantl |  |-  ( ( ( A e. RR /\ B e. RR /\ A <_ B ) /\ n e. ( 1 ... ( |_ ` B ) ) ) -> n e. NN ) | 
						
							| 4 |  | vmacl |  |-  ( n e. NN -> ( Lam ` n ) e. RR ) | 
						
							| 5 | 3 4 | syl |  |-  ( ( ( A e. RR /\ B e. RR /\ A <_ B ) /\ n e. ( 1 ... ( |_ ` B ) ) ) -> ( Lam ` n ) e. RR ) | 
						
							| 6 |  | vmage0 |  |-  ( n e. NN -> 0 <_ ( Lam ` n ) ) | 
						
							| 7 | 3 6 | syl |  |-  ( ( ( A e. RR /\ B e. RR /\ A <_ B ) /\ n e. ( 1 ... ( |_ ` B ) ) ) -> 0 <_ ( Lam ` n ) ) | 
						
							| 8 |  | flword2 |  |-  ( ( A e. RR /\ B e. RR /\ A <_ B ) -> ( |_ ` B ) e. ( ZZ>= ` ( |_ ` A ) ) ) | 
						
							| 9 |  | fzss2 |  |-  ( ( |_ ` B ) e. ( ZZ>= ` ( |_ ` A ) ) -> ( 1 ... ( |_ ` A ) ) C_ ( 1 ... ( |_ ` B ) ) ) | 
						
							| 10 | 8 9 | syl |  |-  ( ( A e. RR /\ B e. RR /\ A <_ B ) -> ( 1 ... ( |_ ` A ) ) C_ ( 1 ... ( |_ ` B ) ) ) | 
						
							| 11 | 1 5 7 10 | fsumless |  |-  ( ( A e. RR /\ B e. RR /\ A <_ B ) -> sum_ n e. ( 1 ... ( |_ ` A ) ) ( Lam ` n ) <_ sum_ n e. ( 1 ... ( |_ ` B ) ) ( Lam ` n ) ) | 
						
							| 12 |  | chpval |  |-  ( A e. RR -> ( psi ` A ) = sum_ n e. ( 1 ... ( |_ ` A ) ) ( Lam ` n ) ) | 
						
							| 13 | 12 | 3ad2ant1 |  |-  ( ( A e. RR /\ B e. RR /\ A <_ B ) -> ( psi ` A ) = sum_ n e. ( 1 ... ( |_ ` A ) ) ( Lam ` n ) ) | 
						
							| 14 |  | chpval |  |-  ( B e. RR -> ( psi ` B ) = sum_ n e. ( 1 ... ( |_ ` B ) ) ( Lam ` n ) ) | 
						
							| 15 | 14 | 3ad2ant2 |  |-  ( ( A e. RR /\ B e. RR /\ A <_ B ) -> ( psi ` B ) = sum_ n e. ( 1 ... ( |_ ` B ) ) ( Lam ` n ) ) | 
						
							| 16 | 11 13 15 | 3brtr4d |  |-  ( ( A e. RR /\ B e. RR /\ A <_ B ) -> ( psi ` A ) <_ ( psi ` B ) ) |