let p, q be Real; :: thesis: (sin . (p + q)) - (sin . p) = (q * (cos . p)) + (q * (Re ((Sum ((q * <i>) P_dt)) * ((cos . p) + ((sin . p) * <i>)))))
(sin . (p + q)) - (sin . p) = (sin . (p + q)) - (Im (Sum ((p * <i>) ExpSeq))) by Def16
.= (Im (Sum (((p + q) * <i>) ExpSeq))) - (Im (Sum ((p * <i>) ExpSeq))) by Def16
.= Im ((Sum (((p * <i>) + (q * <i>)) ExpSeq)) - (Sum ((p * <i>) ExpSeq))) by COMPLEX1:19
.= Im (((Sum ((p * <i>) ExpSeq)) * (q * <i>)) + (((q * <i>) * (Sum ((q * <i>) P_dt))) * (Sum ((p * <i>) ExpSeq)))) by Th58
.= Im ((((cos . p) + ((sin . p) * <i>)) * (q * <i>)) + (((q * <i>) * (Sum ((q * <i>) P_dt))) * (Sum ((p * <i>) ExpSeq)))) by Lm3
.= Im ((((cos . p) + ((sin . p) * <i>)) * (q * <i>)) + (((q * <i>) * (Sum ((q * <i>) P_dt))) * ((cos . p) + ((sin . p) * <i>)))) by Lm3
.= (Im ((- (q * (sin . p))) + ((q * (cos . p)) * <i>))) + (Im (((q * <i>) * (Sum ((q * <i>) P_dt))) * ((cos . p) + ((sin . p) * <i>)))) by COMPLEX1:8
.= (q * (cos . p)) + (Im ((q * <i>) * ((Sum ((q * <i>) P_dt)) * ((cos . p) + ((sin . p) * <i>))))) by COMPLEX1:12
.= (q * (cos . p)) + (q * (Re ((Sum ((q * <i>) P_dt)) * ((cos . p) + ((sin . p) * <i>))))) by Lm12 ;
hence (sin . (p + q)) - (sin . p) = (q * (cos . p)) + (q * (Re ((Sum ((q * <i>) P_dt)) * ((cos . p) + ((sin . p) * <i>))))) ; :: thesis: verum