DSL EXPRESSION:
$d=$x/@ox; @ox=$x


AST:
* statement block
    * assignment "="
        * direct field value "d"
        * operator "/"
            * direct field value "x"
            * direct oosvar value "ox"
    * assignment "="
        * direct oosvar value "ox"
        * direct field value "x"

a   b   i  x          y          d           x_ratio
pan pan 1  0.34679014 0.72680286 0.34679014  1
eks pan 2  0.75867996 0.52215111 2.18772066  2.18772066
wye wye 3  0.20460331 0.33831853 0.26968329  0.26968329
eks wye 4  0.38139939 0.13418874 1.86409204  1.86409204
wye pan 5  0.57328892 0.86362447 1.50311964  1.50311964
zee pan 6  0.52712616 0.49322129 0.91947732  0.91947732
eks zee 7  0.61178406 0.18788492 1.16060273  1.16060273
zee wye 8  0.59855401 0.97618139 0.97837464  0.97837464
hat wye 9  0.03144188 0.74955076 0.05252972  0.05252972
pan wye 10 0.50262601 0.95261836 15.98587814 15.98587814
