This function constructs the inverse of `
transform`
. If `
T`
is `
transform`
and `
T'`
is its inverse, then `
TT`
' = I. If `
into`
is non-nil it is modified to contain `
T'`
and returned, otherwise a new transform is constructed and returned.

See graphics-state for details of how a transform is used.

*CAPI User Guide and Reference Manual (Unix version) - 25 Feb 2015*