I have tried to simulate a memristor model which already working well on LTspice.
but gives a syntax error in qspice. can anyone help debug?

Knowm Mean Metastable Switch Memristor SPICE Model

Copyright Tim Molter Knowm Inc. 2017

Connections:

TE: Top electrode

BE: Bottom electrode

XSV: External connection to plot state variable

that is not used otherwise
.SUBCKT MEM_KNOWM TE BE XSV
 Ron: Minimum device resistance
 Roff: Maximum device resistance
 Von: Threshold voltage to turn device on
 Voff: Threshold voltage to turn device off
 TAU: Time constant
 T: Temperature
.params Ron=500 Roff=1500 Voff=0.27 Von=0.27 TAU=0.0001 T=298.5 x0=0

Function G(V(t))  Describes the device threshold
.func G(V) = V/Ron+(1V)/Roff 
Function F(V(t),x(t))  Describes the SV motion
.func F(V1,V2) = (1/TAU)((1/(1+exp(1/(Tboltz/echarge)(V1Von))))(1V2)(1(1/(1+exp(1/(Tboltz/echarge)(V1+Voff)))))*V2 
Memristor IV Relationship
.func IVRel(V1,V2) = V1*G(V2) 
Circuit to determine state variable

dx/dt = F(V(t),x(t))*G(V(t))
Cx XSV 0 {1}
.ic V(XSV) = x0
Gx 0 XSV value={F(V(TE,BE),V(XSV,0))} 
Current source for memristor IV response
Gmem TE BE value={IVRel(V(TE,BE),V(XSV,0))}
.ENDS MEM_KNOWM