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  0.3467901443380824  0.7268028627434533  0.3467901443380824  1
eks pan 2  0.7586799647899636  0.5221511083334797  2.187720663855815   2.187720663855815
wye wye 3  0.20460330576630303 0.33831852551664776 0.269683285788292   0.269683285788292
eks wye 4  0.38139939387114097 0.13418874328430463 1.8640920411460684  1.8640920411460684
wye pan 5  0.5732889198020006  0.8636244699032729  1.5031196404986713  1.5031196404986713
zee pan 6  0.5271261600918548  0.49322128674835697 0.919477320918588   0.919477320918588
eks zee 7  0.6117840605678454  0.1878849191181694  1.1606027302102375  1.1606027302102375
zee wye 8  0.5985540091064224  0.976181385699006   0.978374638513558   0.978374638513558
hat wye 9  0.03144187646093577 0.7495507603507059  0.05252972327071228 0.05252972327071228
pan wye 10 0.5026260055412137  0.9526183602969864  15.985878138211305  15.985878138211305
