condition problems about midica HOT 1 CLOSED

CALL f()         // IF (bug!)
CALL f(IF)       // IF (as expected)
CALL f(UNKNOWN)  // ELSE (as expected)

FUNCTION f
	{ if $[0] == IF
		0  a  /4  l=IF
	}
	{ else
		0  b  /4  l=ELSE
	}
END

CALL f()         // ELSE (as expected)
CALL f(IF)       // IF (as expected)
CALL f(UNKNOWN)  // ELSE (as expected)

FUNCTION f
	{
		{ if $[0] == IF
			0  a  /4  l=IF_
		}
		{ else
			0  b  /4  l=ELSE_
		}
	}
END