1. A computer program product for use with a Multi-Level Data Structure (MLDS) having a computer usable medium containing computer readable program code embodied in said medium for causing a Delta Pattern Matching Syntax (DPMS) program to be executed for evaluating conditions in said MLDS, wherein the DPMS program is encapsulated within a marked command of said computer readable program code comprising; a first module for causing the data processing system to 1) initialize a data processing environment for processing said DPMS program by means of the CPU implementing a set of program language instructions, and 2) process the marked command for mapping constructs of the DPMS program to DPMS constructs in said programming language for placement in an encoded structure; and a second module for causing the data processing system to execute the DPMS constructs in the MLDS using a DPMS interpreter stored in the data processing system memory; wherein the DPMS constructs represent a set of instructions specifying procedural rules of operation on the MLDS, wherein the DPMS interpreter can query and modify the MLDS using the DPMS constructs, wherein the DPMS interpreter communicates with the MLDS using a class methods of the MLDS objects, and wherein the evaluation of a DPMS statement tests for conditions in the MLDS, producing a result