spatial <->
x_to: =*
spatial <->
y_from: =*
spatial <->
y_to: =*
spatial <->
x_from: =*These equations define the reference points on both graphical
objects constrained. They should be defaulted or specified in pairs: if
spatial<-x_from
is specified so must spatial<-x_to
and likewise for spatial<-y_from
and
spatial<-y_to.
The reference points of both objects are constrained to be at the
same location.
During the evaluation of the = object, the following variables are
available:
| xref | the x coordinate of the reference-point |
| yef | the y coordinate of the reference-point |
| x | spatial<-x of the
graphical's graphical<-area |
| y | spatial<-y |
| w | spatial<-width |
| h | spatial<-height |
