This should be in Oz programming language.

The statement X = a # b # c abbreviates X = '#'(a b c), which constructs a tuple with label '#' and fields a, b and c. For example, the following two calls do the same thing: {Browse '#'(a b c)} {Browse a#b#c} Pairs are often used as elements of lists. These lists are called pairlists (also called lists of pairs). For example, the following list is a pairlist: [a#1 b#2 c#3]. But both pairs and cons are constructed with infix operators ('#' and '|'). Give examples which show that '#' has a higher precedence (binds tighter) than '|'.