parent checks in arithmetic

[tthsqe12]

It looks like parent checks were not inserted in any(?) of the methods for number arithmetic. This is obviously needed.

julia> using Singular

julia> Fabcde,(a,b,c,d,e)=FunctionField(Fp(7),["a","b","c","d","e"])
(Function Field over Finite Field of Characteristic 7 with transcendence basis n_transExt[(a), (b), (c), (d), (e)], n_transExt[(a), (b), (c), (d), (e)])

julia> Fx,(x,) = FunctionField(Fp(5), ["x"])
(Function Field over Finite Field of Characteristic 5 with transcendence basis n_transExt[(x)], n_transExt[(x)])

julia> a*b*c*d*e+x
(a*b*c*d*e+c*d^49*e^582112)