1.

with(RegularChains):

with(ConstructibleSetTools):

source1 := PolynomialRing([a,b,c]);

target1 := PolynomialRing([e1,e2,e3,e4]);

source1list := [eq2a, eq3a,eq4a];

target1list := [eq2b, eq3b, eq4b,eq5b];

cs := PolynomialMapPreimage(target1list, source1list, source1, target1);

Error, (in RegularChains:-ConstructibleSetTools:-PolynomialMapPreimage) number of map functions is different from number of variables in target space

in maple 15 do not have error, however now it has error for the code below

with(RegularChains): with(RegularChains): with(ConstructibleSetTools):

source1 := PolynomialRing([e1, e2, e3]);

target1 := PolynomialRing([a, b, c]);

source1list := [-1*e1+2*e2+*e3, -1*e1+2*e2+*e3, -1*e1+2*e2+*e3];

target1list := [.....]; cs :=

PolynomialMapPreimage(target1list, source1list, source1, target1);

Error, invalid product/quotient