1. A method for graph syntax validation comprising: receiving, by a processor, (i) an input graph that contains one or more input graph nodes, the input graph is checked for use of valid syntax or invalid syntax, (ii) transformation rules, and (iii) a minimal valid graph, wherein the input graph nodes indicate, in a graph notation, types of nodes, wherein the types of the nodes include functions, events, and gateways, where a syntax is defined by the transformation rules; transforming, by the processor in response to receiving the input graph, the input graph toward the minimal valid graph using the transformation rules, each of the transformation rules includes a source pattern and a target pattern, further comprising, in the transforming step, source pattern-matching by comparing the input graph with the source pattern of the transformation rules and determining whether the input graph matches the source pattern of one or more transformation rules; and rule-executing, by replacing the input graph nodes that are determined to match the source pattern of one or more transformation rules with the target patterns for the one or more transformation rules, wherein the transforming recurs until either the input graph has been determined to be reduced to the minimal valid graph indicating that the input graph uses the valid syntax, or until it is determined that none of the transformation rules match the input graph indicating that the input graph uses an invalid syntax; and outputting, by the processor, after the transforming, a result indicating either that the input graph is determined to use the valid syntax or the input graph is determined to use the invalid syntax.