modified print function s.t. it prints lrx style brackets; fixed bug in assign child
Merge branch 'chris_kira_semantic_analysis' of https://github.com/dmb2168/PLT into chris_kira_semantic_analysis
added test for assigning and accessing children e.g. t%0 = t2
Merge pull request #15 from dmb2168/chris_kira_semantic_analysis

Chris kira semantic analysis