root machine added to DefinitionParser.__parse* methods because when something is omitted around a binary expression, root has to go there (and not always @parent, previous implementation)
root machine added to DefinitionParser.__parse* methods because when
something is omitted around a binary expression, root has to go there
(and not always @parent, previous implementation)

kornai/pymachine,Eszti/pymachine,kornai/pymachine,recski/pymachine,recski/pymachine,Eszti/pymachine