: do-row ( exchange-with row# -- )\r
[ exchange-rows ] keep\r
[ first-col ] keep\r
- dup 1+ rows-from clear-col ;\r
+ dup 1 + rows-from clear-col ;\r
\r
: find-row ( row# quot -- i elt )\r
[ rows-from ] dip find ; inline\r
\r
: (echelon) ( col# row# -- )\r
over cols < over rows < and [\r
- 2dup pivot-row [ over do-row 1+ ] when*\r
- [ 1+ ] dip (echelon)\r
+ 2dup pivot-row [ over do-row 1 + ] when*\r
+ [ 1 + ] dip (echelon)\r
] [\r
2drop\r
] if ;\r