\beginfig(30) pair q; pair q; p := (0, 0); q := (2cm, 0); draw p; draw q; \endfig; end
This is MetaPost, Version 0.993 (Web2C 7.5.6)
(graph.mp
>> p
>> (0,0)
! Equation cannot be performed (numeric=pair).
<to be read again>
;
l.4 p := (0, 0);
vielen Dank schonmal,
ferrair987

