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Macaulay2 website
Cremona
::
isInverseMap(RationalMap,RationalMap)
isInverseMap(RationalMap,RationalMap)  checks whether two rational maps are one the inverse of the other
Synopsis
Function:
isInverseMap
Usage:
isInverseMap(phi,psi)
Inputs:
phi
,
a
rational map
psi
,
a
rational map
Outputs:
a
Boolean value
, whether
phi * psi == 1 and psi * phi == 1
Consequences:
If the answer is affirmative, then the system will be informed and so commands like 'inverse phi' will execute fast.
See also
RationalMap == RationalMap
 equality of rational maps
RationalMap * RationalMap
 composition of rational maps
isInverseMap(RingMap,RingMap)
 checks whether a rational map is the inverse of another
inverse(RationalMap)
 inverse of a birational map
forceInverseMap
 declare that two rational maps are one the inverse of the other
Ways to use this method:
isInverseMap(RationalMap,RationalMap)
 checks whether two rational maps are one the inverse of the other