RegularChains[ConstructibleSetTools][RepresentingRegularSystems] - return the list of regular systems in a constructible set
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Calling Sequence
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RepresentingRegularSystems(cs, R)
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Parameters
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cs
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constructible set
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R
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polynomial ring
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Description
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The command RepresentingRegularSystems(cs,R) returns a list of regular systems which defines the constructible set cs, that is, a list of regular systems (whose polynomials belong to R) such that the union of their zero sets is exactly equal to cs.
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Recall that every constructible set built by the ConstructibleSetTools module is in fact represented by a list of regular systems representing it in the above sense.
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See ConstructibleSetTools and RegularChains for the related mathematical concepts, in particular for the ideas of a constructible set, a regular system, and a regular chain.
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The command RepresentingRegularSystems is part of the RegularChains[ConstructibleSetTools] package, so it can be used in the form RepresentingRegularSystems(..) only after executing the command with(RegularChains[ConstructibleSetTools]). However, it can always be accessed through the long form of the command by using RegularChains[ConstructibleSetTools][RepresentingRegularSystems](..).
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Examples
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First, define a polynomial ring and two polynomials of .
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Using GeneralConstruct, construct a constructible set from the common solutions of and which do not cancel
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Now retrieve the regular systems from cs.
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Next extract the representing chains and inequations
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The first inequation is since this polynomial can vanish inside the quasi-component of the first regular chain.
The second inequation is simply since cannot vanish inside the quasi-component of the second regular chain.
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