is mentioned by

Thm* x,y:, n:. ((x+y) rem n) = (((x rem n)+(y rem n)) rem n)+if (x+y < 0)(0 < (((x rem n)+(y rem n)) rem n))-|n| ;((((x rem n)+(y rem n)) rem n) < 0)(0 < x+y)|n| else 0 fi	[rem_add]
Thm* a:, n:, q,r:. a = qn+r |r| < |n| (r < 0 a < 0) (r > 0 a > 0) q = (a n) & r = (a rem n)	[div_rem_unique]
Thm* a:, n:. a = (a n)n+(a rem n) & |a rem n| < |n| & ((a rem n) < 0 a < 0) & ((a rem n) > 0 a > 0)	[div_rem_properties]
Thm* a,b:. |ab| = |a||b|	[absval_mul]

In prior sections: int 2 num thy 1

Try larger context: Graphs