Question: When running a for do cycle the first two solutions are the same

restart

tmin:=10: #°C

tmax:=70: #°C

Tmin:=tmin+273.15:

Tmax:=tmax+273.15:

T:='T':

i:=0:

for T from Tmin by 2 to Tmax+1.25 do
i:=i+1:
a12:=2305.28444347652 - 9.14490843016421*T + 0.00680052257590234*T^2:
a21:=-6665.24838284836 + 46.0897018087247*T - 0.0694991633494123*T^2:
alfa:=0.3:
x2:=1-x1:
lng1:=x2^2*(tau21*(G21/(x1+x2*G21))^2+tau12*(G12/((x2+x1*G12)^2))):
lng2:=x1^2*(tau12*(G12/(x2+x1*G12))^2+tau21*(G21/((x1+x2*G21)^2))):
G12:=exp(-alfa*tau12):
G21:=exp(-alfa*tau21):
tau12:=a12/T:
tau21:=a21/T:
lnga1:=subs(x1=xa1,lng1):
lngb1:=subs(x1=xb1,lng1):
lnga2:=subs(x1=xa1,lng2):
lngb2:=subs(x1=xb1,lng2):
r1:=lnga1+ln(xa1)=lngb1+ln(xb1):
r2:=lnga2+ln(1-xa1)=lngb2+ln(1-xb1):
r:=fsolve({r1,r2},{xa1=0..0.22,xb1=0.22..1}):
assign(r):
xA1[i]:=xa1: xB1[i]:=xb1:
print(i,T,xA1[i],xB1[i]);
unassign('r1','r2','r','xa1','xb1'):
od: