is mentioned by

Thm* a,b:. (a -- (a -- b)) = imin(a;b)	[ndiff_ndiff_eq_imin]
Thm* a,b,c:. aimin(b;c) ab & ac	[imin_ub]
Thm* a,b,c:. imin(a;b)c ac bc	[imin_lb]
Thm* a,b,c:. imin(a;b)+c = imin(a+c;b+c)	[imin_add_r]
Thm* a,b:. imin(a;b) = imin(b;a)	[imin_com]
Thm* a,b,c:. imin(a;imin(b;c)) = imin(imin(a;b);c)	[imin_assoc]
Thm* a,b:. -imin(a;b) = imax(-a;-b)	[minus_imin]
Thm* a,b:. -imax(a;b) = imin(-a;-b)	[minus_imax]

Try larger context: StandardLIB