Match the following: A- Formal mathematical transformation: B- Formal process model: C-Formal Specifications: D-Formal System development: 1- Here the formal mathema- tical representation of the system takes place. 2- It is a starting point for process analysis. It is abstract and only defines the principal process activities and deliverables. 3-Specifications expressed in a language whose vocabulary, syntax and semantics are formally defined. 4-It is more common to waterfall model, but here the development process is based on formal mathematical transformation of a system specification to an exactable program.