: run ( pt2 pt1 -- n ) [ first ] bi@ - ;
: slope ( pt pt -- slope ) [ rise ] [ run ] 2bi / ;
: midpoint ( point point -- point ) v+ 2 v/n ;
-: linear-solution ( pt pt -- x ) [ drop first2 ] [ slope ] 2bi / - ;
\ No newline at end of file
+: linear-solution ( pt pt -- x ) [ drop first2 ] [ slope ] 2bi / - ;