diff --git a/base/grammar.rkt b/base/grammar.rkt
index 50224fa..1f29a2e 100644
--- a/base/grammar.rkt
+++ b/base/grammar.rkt
@@ -14,7 +14,7 @@
   [cf-grammar-start-rules (-> cf-grammar? (set/c cf-production-rule? #:kind 'immutable))]
   [make-cf-grammar (-> #:rules (sequence/c cf-production-rule?) #:start-symbol any/c cf-grammar?)]
   [make-cf-production-rule
-   (-> #:symbol any/c #:substitution (sequence/c grammar-symbol?) #:action semantic-action?
+   (-> #:nonterminal any/c #:substitution (sequence/c grammar-symbol?) #:action semantic-action?
        cf-production-rule?)]))
 
 
@@ -64,5 +64,7 @@
   (cf-grammar (sequence->vector rules) start))
 
 
-(define (make-cf-production-rule #:symbol symbol #:substitution substitution #:action action)
-  (cf-production-rule symbol action (sequence->vector substitution)))
+(define (make-cf-production-rule #:nonterminal nonterminal
+                                 #:action action
+                                 #:substitution substitution)
+  (cf-production-rule nonterminal action (sequence->vector substitution)))
diff --git a/parser/earley.rkt b/parser/earley.rkt
index f31b8f6..0d68425 100644
--- a/parser/earley.rkt
+++ b/parser/earley.rkt
@@ -250,26 +250,26 @@
     ;; Grammar and input taken from https://en.wikipedia.org/wiki/Earley_parser#Example
     (define P-rule
       (make-cf-production-rule
-       #:symbol 'P #:action (label-action 'P) #:substitution (list (nonterminal-symbol 'S))))
+       #:nonterminal 'P #:action (label-action 'P) #:substitution (list (nonterminal-symbol 'S))))
     (define S-rule0
       (make-cf-production-rule
-       #:symbol 'S
+       #:nonterminal 'S
        #:action (label-action 'S0)
        #:substitution (list (nonterminal-symbol 'S) (terminal-symbol '+) (nonterminal-symbol 'M))))
     (define S-rule1
       (make-cf-production-rule
-       #:symbol 'S #:action (label-action 'S1) #:substitution (list (nonterminal-symbol 'M))))
+       #:nonterminal 'S #:action (label-action 'S1) #:substitution (list (nonterminal-symbol 'M))))
     (define M-rule0
       (make-cf-production-rule
-       #:symbol 'M
+       #:nonterminal 'M
        #:action (label-action 'M0)
        #:substitution (list (nonterminal-symbol 'M) (terminal-symbol '*) (nonterminal-symbol 'T))))
     (define M-rule1
       (make-cf-production-rule
-       #:symbol 'M #:action (label-action 'M1) #:substitution (list (nonterminal-symbol 'T))))
+       #:nonterminal 'M #:action (label-action 'M1) #:substitution (list (nonterminal-symbol 'T))))
     (define T-rule
       (make-cf-production-rule
-       #:symbol 'T #:action (label-action 'T) #:substitution (list (terminal-symbol 'number))))
+       #:nonterminal 'T #:action (label-action 'T) #:substitution (list (terminal-symbol 'number))))
     (define arithmetic-grammar
       (make-cf-grammar
        #:rules (list P-rule S-rule0 S-rule1 M-rule0 M-rule1 T-rule) #:start-symbol 'P))