thus Sum (digits (2650,10)) =
(Sum <%0,5,6%>) + (Sum <%2%>)
by Th1215, AFINSQ_2:55
.=
((Sum <%0,5%>) + (Sum <%6%>)) + (Sum <%2%>)
by AFINSQ_2:55
.=
((0 + 5) + (Sum <%6%>)) + (Sum <%2%>)
by AFINSQ_2:54
.=
((0 + 5) + 6) + (Sum <%2%>)
by AFINSQ_2:53
.=
11 + 2
by AFINSQ_2:53
.=
13
; verum