package documentation

Undocumented

Module 99_math_z3 extension to support math.ceil and math.floor floor and ceil by default will just bypassed. Specifically target ceil division (math.ceil(float(x)/y))
Module infer_z3 additional extension file to substitute all of the field defined in substitutes. Substituted node is needed for 'flattening' a node with respect to a particular node, because the usual `infer` will give us `uninferable` result...