thus Sum (digits (2024,10)) = (Sum <%4,2,0%>) + (Sum <%2%>) by Th886, AFINSQ_2:55
.= ((Sum <%4,2%>) + (Sum <%0%>)) + (Sum <%2%>) by AFINSQ_2:55
.= ((4 + 2) + (Sum <%0%>)) + (Sum <%2%>) by AFINSQ_2:54
.= ((4 + 2) + 0) + (Sum <%2%>) by AFINSQ_2:53
.= 6 + 2 by AFINSQ_2:53
.= 8 ; :: thesis: verum