func lim1(x, y, z int) {
	// Test relations between signed and unsigned limits.
	if x > 5 {
		if uint(x) > 5 { // ERROR "Proved Less64U$"
			return
		}
	}
	if y >= 0 && y < 4 {
		if uint(y) > 4 { // ERROR "Disproved Less64U$"
			return
		}
		if uint(y) < 5 { // ERROR "Proved Less64U$"
			return
		}
	}
	if z < 4 {
		if uint(z) > 4 { // Not provable without disjunctions.
			return
		}
	}
}

(Less32 x y) => (SGT (SignExt32to64 y) (SignExt32to64 x))
(Less64 x y) => (SGT y x)
(Less(32|64)F x y) => (FPFlagTrue (CMPGT(F|D) y x)) // reverse operands to work around NaN

(Less8U x y)  => (SGTU (ZeroExt8to64 y) (ZeroExt8to64 x))
(Less16U x y) => (SGTU (ZeroExt16to64 y) (ZeroExt16to64 x))
(Less32U x y) => (SGTU (ZeroExt32to64 y) (ZeroExt32to64 x))
(Less64U x y) => (SGTU y x)

(RotateLeft32 ...) => (ROLW ...)
(RotateLeft64 ...) => (ROL  ...)

(Less64  ...) => (SLT  ...)
(Less32  x y) => (SLT  (SignExt32to64 x) (SignExt32to64 y))
(Less16  x y) => (SLT  (SignExt16to64 x) (SignExt16to64 y))
(Less8   x y) => (SLT  (SignExt8to64  x) (SignExt8to64  y))
(Less64U ...) => (SLTU ...)
(Less32U x y) => (SLTU (ZeroExt32to64 x) (ZeroExt32to64 y))

	{name: "Less16U", argLength: 2, typ: "Bool"},
	{name: "Less32", argLength: 2, typ: "Bool"},
	{name: "Less32U", argLength: 2, typ: "Bool"},
	{name: "Less64", argLength: 2, typ: "Bool"},
	{name: "Less64U", argLength: 2, typ: "Bool"},
	{name: "Less32F", argLength: 2, typ: "Bool"},
	{name: "Less64F", argLength: 2, typ: "Bool"},

	{name: "Leq8", argLength: 2, typ: "Bool"},  // arg0 <= arg1, signed