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document {
Key => {
selectVariables,
(selectVariables, List, PolynomialRing)
},
Headline => "make a subring of a polynomial ring generated by selected variables",
Usage => "(S,F) = selectVariables(v,R)",
Inputs => {
"v" => {"a sorted list of numbers specifying which variables to select"},
"R"
},
Outputs => {
"S" => PolynomialRing => {"a polynomial ring generated as a subring of R by the variables whose indices
occur in the list v, together with the induced monomial ordering"
},
"F" => RingMap => {"the inclusion map from S to R"}
},
EXAMPLE lines ///
R = QQ[a..h, Weights => 1..8]
(S,F) = selectVariables({2,4}, R);
describe S
options S
F
///
}
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