Singular Manual: dmodGeneralAssumptionCheck

| ##### 7.5.13.0. dmodGeneralAssumptionCheck Procedure from library `dmodloc.lib` (see dmodloc_lib). Usage: dmodGeneralAssumptionCheck(); Return: nothing, but checks general assumptions on the basering Note: This procedure checks the following conditions on the basering R and prints an error message if any of them is violated: - R is the n-th Weyl algebra over a field of characteristic 0, - R is not a qring, - for all 1<=i<=n the identity var(i+n)*var(i)=var(i)*var(i+1)+1 holds, i.e. the sequence of variables is given by x(1),...,x(n),D(1),...,D(n), where D(i) is the differential operator belonging to x(i). Example:
    LIB "dmodloc.lib";
    ring r = 0,(x,D),dp;
    dmodGeneralAssumptionCheck(); // prints error message
    ==>    ? Basering is not a Weyl algebra
    ==>    ? leaving dmodloc.lib::dmodGeneralAssumptionCheck (0)
    def W = Weyl();
    setring W;
    dmodGeneralAssumptionCheck(); // returns nothing

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