SLEW
VIN PULSE (-5 +5 0.5U 0.5U 50U 100U)
X1 1 4 2 3 4 ;subckt name
VPOS 2 0 DC 15
VNEG 3 0 DC -15
.LIB ;lib filename
.TRAN 1U 200U 0.1U UIC 
.IC V(4)=0
.PROBE V(4) V(1)
.end