`Gg.P`

Implemented by all point types.

`dim`

is the dimension of points of type `t`

.

The type for matrices representing linear transformations of *homogenous* `dim`

space.

`val o : t`

`o`

is the point whose coordinates are all zero.

`tr m p`

is the affine transform in homogenous `dim`

space of the *point* `p`

by `m`

.

**Note.** Since `m`

is supposed to be affine the function ignores the last row of `m`

. `p`

is treated as a finite point (its last coordinate in homogenous space is 1).