Removal of unit production:


Production in form of Non-terminal (variable)  Single Non-terminal (Variable) (V → V) is called Unit production like A → B


Unit production increases the number of steps and as well as complexity at the time of generating language from grammar. 


Removal of unit production does not change the grammar.


Procedure to remove unit production:


To discuss the procedure we consider a grammar as an example.



Step 1:


First, we create a dependency graph of all unit production.




Step 2:


Now we write grammar without unit production:



Whatever we derive from B, we same way derive from A because A ⇒ B, and same things happen for all production.


New grammar: