Step 2: Relational graph: We can use visual language (generated using visual grammar) to specify the relations for the IC cards. Result is a relational graph. In the relational graph, the subgraphs are the patterns. Each grammar rule can thus be a pattern. (Picnic is a relation between organizer and attendees)
Step 3: IC structure: Transform the relational graph into IC structure. In the IC structure, the substructures are the patterns.
Comments: (i) Step 1 and Step 2 may be missing, if we start from IC structure directly
(ii) If we start from IC card, we go to Step 2 directly
(iii) Problem of context. Some can be absorbed within the IC (i.e. in terms of f and g). But some may be explict, i.e. time, weather,etc.
(iv) Need formal transformation rules