17.4 Operations for Unknowns

The operators +, -, * and / are used for addition, subtraction, multiplication and division of unknowns and cyclotomics. The result will be a new unknown except in one of the following cases:

Multiplication with zero yields zero, and multiplication with one or addition of zero yields the old unknown.

    gap> Unknown() + 1; Unknown(2) + 0; last * 3; last * 1; last * 0;
    Unknown(2010)
    Unknown(2)
    Unknown(2011)
    Unknown(2011)
    0

Note that division by an unknown causes an error, since an unknown might stand for zero.

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