45) Consider a grammar : G = ( { x , y ) , { s , x , y } , p , s) where elements of parse :
S--> x y
S -->y x
x--> x z
x--> x
y--> y
z--> z
The language L generated by G most accurately is called

46) Consider a grammar : G = { { S } , { 0 , 1 } , p , s } where elements of p are:
S --> ss
S--> 0S1
S--> 1S0
S--> empty
The grammar will generate

47) A grammar that produces more than one parse tree for some sentence is called

48) Given a grammar G a production of G with a dot at some position of the right side is called

49) If a language is denoted by a regular expression L = ( x )* (x | y x ) , then which of the following is not a legal string within L ?