For each grammar, the start symbol is the LHS of the first rule.

For a given grammar, the symbols that appear on a LHS are
nonterminals; the others are terminals.

The first and last grammars can use predictive parsing.
The second and fourth have direct or indirect left recursion.


S -> NP VP
NP -> Det N
VP -> V NP
Det -> the
V -> chased
N -> dog
N -> cat


Expr -> Expr Op Expr
Expr -> < Expr >
Expr -> Var
Var -> x
Var -> y
Op -> *
Op -> +


Expr -> Term Op Expr
Expr -> Term
Term -> Factor Op Term
Term -> Factor
Factor -> Var
Factor -> < Expr >
Var -> x
Var -> y


A -> w
B -> x
C -> y
D -> z
A -> D w
C -> B x
D -> C y
B -> A z
  

Cond -> if Test then Block else Block endif
Cond -> if Test then Block endif
Test -> < Var Op Var> 
Var -> x
Var -> y
Op -> =
Op -> /=
Block -> begin Statements end
Block -> begin end
Statements -> Statement
Statements -> Statement Statements
Statement -> Var := Var


Cond -> ShortIf RestIf
ShortIf -> if Test then Block
RestIf -> else Block endif
RestIf -> endif
Test -> < Var Op Var> 
Var -> x
Var -> y
Op -> =
Op -> /=
Block -> begin RestBlock
RestBlock -> end
RestBlock -> Statement Statements
Statements -> end
Statements -> Statement Statements
Statement -> Var := Var