Two custom infix operators belong to precedence groups with no relative ordering declared between them. What happens at `a <> b >< c`?
precedencegroup GroupA { associativity: left }
precedencegroup GroupB { associativity: left }
infix operator <> : GroupA
infix operator >< : GroupB
// a, b, c are Ints with both operators defined
let r = a <> b >< c