An inverse query engine that uses an instruction tree to represents the queries to be applied against input, instead of applying each query individually. Each node in the instruction tree represents executable code. Each branch of the instruction tree when executed from the root node to a terminating branch node represents the instructions to be executed to process that query against the input. The instruction tree is forward-only in that once a node in a tree is processed against an input, that executable code associated with that node is not ever processed again for that node. Accordingly, processing resources and time is conserved.