[Help-gnucap] Help: error using parameters in a subcircuit

[Edgar Ricardo Perdomo Ayala]

Hello,

I'm using a subcircuit to model a three-wire transformer (as recommended by
al davis
http://lists.gnu.org/archive/html/help-gnucap/2008-08/msg00003.html)

*test
.subckt tx (a1 a2 b1 b2 c1 c2)
.param M12 = 'K12 * sqrt (L1 * L2)'
.param M23 = 'K23 * sqrt (L2 * L3)'
.param M13 = 'K13 * sqrt (L1 * L3)'
l1 (a3 a2) 'L1'
l2 (b3 b2) 'L2'
l3 (c3 c2) 'L3'
e21 (a4 a3 b3 b2) 'M12 / L2'
e31 (a1 a4 c3 c2) 'M13 / L3'
e12 (b4 b3 a3 a2) 'M12 / L1'
e32 (b1 b4 c3 c2) 'M23 / L3'
*originally e32 (b2 b4 c3 c2) 'M23 / L3'
e13 (c4 c3 a3 a2) 'M13 / L1'
e23 (c1 c4 b3 b2) 'M23 / L2'
*originally e23 (c2 c4 b3 b2) 'M23 / L2'
.ends

*---test circuit
Xt1 vin 0 v1 0 v2 0 tx (L1=1u L2=1u L3=10m
+K12=0.9  K13=0.9 K23=0.9)
rl1 v1 0 100k
rl2 v2 0 100k
V vin 0 press 0 1.5 1m 1m 1m
.print tran v (vin) v (vout)
.tran 0 5m 10u > output.plot
.end

circuit that I put in the test.net file for ease of editing

then in gnucap I give the command
>get test.net
and I get the following error
*test
parameter M12 / L2 has no value
parameter M13 / L3 has no value
parameter M12 / L1 has no value
parameter M23 / L3 has no value
parameter M13 / L1 has no value
parameter M23 / L2 has no value

and output.plot is empty
what am I doing wrong?