is mentioned by

Thm* a:, n:, p,q:. Div(a;n;p) Div(a;n;q) p = q	[div_unique]
Thm* a:, n:. q:. Div(a;n;q) & (a n) = q	[div_elim]
Thm* a:, n:. Div(a;n;a n)	[div_fun_sat_div_nrel]
Def Rem(a;n;r) == q:. Div(a;n;q) & qn+r = a	[rem_nrel]

Try larger context: StandardLIB