List.Lengthtype 'a t = ( 'a list, int ) Sigs.predicate2val equal : 'a tequal l len returns true if List.length l = len, false otherwise.
val gte : 'a tgte l len returns true if List.length l >= len, false otherwise.
val gt : 'a tgt l len returns true if List.length l > len, false otherwise.
val lte : 'a tlte l len returns true if List.length l <= len, false otherwise.
val lt : 'a tlt l len returns true if List.length l < len, false otherwise. p