A transformation process determines whether a predicate of a rule matches a given node of tree structured data containing a set of nodes and, when the predicate of a rule matches the given node, applies a function of an identified rule to the node to generate a compound result and an interim mutated output document, and when the compound result contains a next node, determines whether the next node is compared with the predicate of a next rule. The transform process includes determining that the next node is processed by a next rule, using the interim mutated output document as input, and determining whether a predicate of a rule matches the next node in a set of nodes. When the predicate of a rule matches the next node, a function of an identified rule is applied to the next node to generate a compound result and interim mutated output document. When the compound result does not contain a next node, a final mutated output document is generated.