# isInverseMap -- checks whether a rational map is the inverse of another

## Synopsis

• Usage:
isInverseMap(phi,psi)
• Inputs:
• phi, , representing a rational map $\Phi:X \dashrightarrow Y$
• psi, , representing a rational map $\Psi:Y \dashrightarrow X$
• Outputs:
• , according to the condition that the composition $\Psi\,\Phi:X \dashrightarrow X$ coincides with the identity of $X$ (as a rational map)

## For the programmer

The object isInverseMap is .