Structure Predicates

IsField(R) : FldFun -> BoolElt
IsEuclideanDomain(R) : FldFun -> BoolElt
IsField(O) : RngFunOrd -> BoolElt
IsPID(R) : FldFun -> BoolElt
IsUFD(R) : FldFun -> BoolElt
IsDivisionRing(R) : FldFun -> BoolElt
IsEuclideanRing(R) : FldFun -> BoolElt
IsDivisionRing(O) : RngFunOrd -> BoolElt
IsPrincipalIdealRing(R) : FldFun -> BoolElt
IsDomain(R) : FldFun -> BoolElt
IsDomain(O) : RngFunOrd -> BoolElt
F eq G : FldFunG, FldFunG -> BoolElt
F ne G : FldFunG, FldFunG -> BoolElt
O1 eq O2 : RngFunOrd, Rng -> BoolElt
O1 ne O2 : RngFunOrd, Rng -> BoolElt
O1 subset O2 : RngFunOrd, RngFunOrd -> BoolElt
Return whether O1 is a subset of O2.
IsGlobal(F) : FldFunG -> BoolElt
Returns true if and only if the algebraic function field F/k is global, i.e. the constant field is a finite field; false otherwise.
IsRationalFunctionField(F) : FldFunG -> BoolElt
Return true if the function field F is isomorphic to a rational function field, (i.e. F is only trivially algebraic).

IsFiniteOrder(O) : RngFunOrd -> BoolElt
Given an order O of a function field, return true if and only if the bottom coefficient ring of O is a polynomial ring.
IsEquationOrder(O) : RngFunOrd -> BoolElt
Given an order O of a function field, return true if and only if the order O is an equation order (i.e. it has been defined by a polynomial and so has a power basis).
IsAbsoluteOrder(O) : RngFunOrd -> BoolElt
Return false if the order O is an extension of another order, otherwise true.
IsMaximal(O) : RngFunOrd -> BoolElt
Given an order O of a function field, return true if and only if the order O is maximal in its field of fractions.
IsTamelyRamified(O) : RngFunOrd -> BoolElt
Return whether the order O is tamely ramified, i.e. no prime ideal of O has residue field with characteristic dividing its ramification index.
IsTotallyRamified(O) : RngFunOrd -> BoolElt
Return whether there is an ideal of the order O which is totally ramified, i.e. its ramification index is equal to the degree of O over its coefficient ring.
IsUnramified(O) : RngFunOrd -> BoolElt
Return whether a finite order O is unramified at the finite places and whether an infinite order O is unramified at the infinite places.
IsWildlyRamified(O) : RngFunOrd -> BoolElt
Return whether there is a prime ideal of the order O which is wildly ramified, i.e. its ramification index is divisible by the characteristic of its residue class field.
IsInKummerRepresentation(K) : FldFun -> BoolElt, FldFunElt
Tests if the global function field K is, in its current representation, a Kummer extension. More specific, this function tests if the defining polynomial is of the form xr - a for some r coprime to the characteristic and if r divides the order of the multiplicative group of the constant field, ie. if the coefficient ring of K contains a primitive r-th root of unity. In case K is in Kummer representation, the element a is returned as a second return value.
IsInArtinSchreierRepresentation(K) : FldFun -> BoolElt, FldFunElt
Tests if a global function field K is, in its current representation, a Artin-Schreier extension, ie. if the defining polynomial of K is of the form xp - x - a where p is the characteristic of K. In this case, the element a is returned as a second return value.
V2.28, 13 July 2023