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Suppose I have an input set of integer vectors, $S = \{v_1,v_2,...,v_n\}$. How do I test if another integer vector $w$ is in the integer span of $S$?

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    You solve the linear system and check whether it has integer solutions.2017-02-10
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    Sure, but how do I check if it has integer solutions?2017-02-10
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    Well, when you have found the solutions…2017-02-10
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    By inspection. If the coordinates of everyone there are integers and the determinant of the coefficient matrix is $1$ or $-1$, then the inverse matrix will have integer entries.2017-02-10
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    It's not as trivial as the other comments would have you believe; the $1$-dimensional case amounts to the study of a linear diophantine equation.2017-02-10
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    @Student what you're considering is a system of linear diophantine equations. Wikipedia has a discussion [over here](https://en.wikipedia.org/wiki/Diophantine_equation#System_of_linear_Diophantine_equations).2017-02-10
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    My intuition is that it should be solving an integer linear program without a target function, but there ought to be an easier way.2017-02-10

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