diff --git a/parser.c b/parser.c
index f7a9404..b5a6b93 100644
--- a/parser.c
+++ b/parser.c
@@ -74,8 +74,8 @@ static void error_expected_tokens(struct parser *parser, size_t num_tokens, ...)
     lex_print_position(&parser->lexer, &parser->eb);
 }
 
-static struct expr_node* parse_subexpression(struct parser *parser);
-int parse_n_expressions(struct parser *parser, struct expr_node **out_nodes, size_t n);
+static struct expr_node* parse_expression(struct parser *parser);
+static int parse_n_expressions(struct parser *parser, struct expr_node **out_nodes, size_t n);
 
 static struct expr_node* parse_bracketed(struct parser *parser) {
     struct expr_node* node;
@@ -85,7 +85,7 @@ static struct expr_node* parse_bracketed(struct parser *parser) {
         return NULL;
     }
 
-    if (!(node = parse_subexpression(parser)))
+    if (!(node = parse_expression(parser)))
         return NULL;
 
     if (!accept_token(parser, TOK_RIGHT_PAREN)) {
@@ -97,7 +97,7 @@ static struct expr_node* parse_bracketed(struct parser *parser) {
     return node;
 }
 
-static struct expr_node *parse_base(struct parser *parser) {
+static struct expr_node *parse_factor(struct parser *parser) {
     struct expr_node *node;
 
     if (token_is(parser, TOK_NUMBER)) {
@@ -163,10 +163,10 @@ static struct expr_node *parse_base(struct parser *parser) {
 
 static struct expr_node *parse_unary(struct parser *parser);
 
-static struct expr_node *parse_factor(struct parser *parser) {
+static struct expr_node *parse_power(struct parser *parser) {
     struct expr_node* node, * new_node, * inner;
 
-    if (!(node = parse_base(parser)))
+    if (!(node = parse_factor(parser)))
         return NULL;
 
     if (accept_token(parser, TOK_POWER)) {
@@ -192,7 +192,7 @@ static struct expr_node* parse_unary(struct parser *parser) {
     if (accept_token(parser, TOK_MINUS)) {
         struct expr_node *node, *inner;
         
-        if (!(inner = parse_factor(parser)))
+        if (!(inner = parse_power(parser)))
             return NULL;
 
         if (!(node = node_create_neg(inner))) {
@@ -205,7 +205,7 @@ static struct expr_node* parse_unary(struct parser *parser) {
     }
 
     accept_token(parser, TOK_PLUS);
-    return parse_factor(parser);
+    return parse_power(parser);
 }
 
 static struct expr_node *parse_term(struct parser *parser) {
@@ -242,7 +242,7 @@ static struct expr_node *parse_term(struct parser *parser) {
     return node;
 }
 
-static struct expr_node *parse_subexpression(struct parser *parser) {
+static struct expr_node *parse_expression(struct parser *parser) {
     struct expr_node *node, *new_node, *inner;
 
     if (!(node = parse_term(parser)))
@@ -276,12 +276,12 @@ static struct expr_node *parse_subexpression(struct parser *parser) {
     return node;
 }
 
-int parse_n_expressions(struct parser *parser, struct expr_node **out_nodes, size_t n) {
+static int parse_n_expressions(struct parser *parser, struct expr_node **out_nodes, size_t n) {
     size_t i;
 
     for (i = 0; i < n; ++i) {
         struct expr_node *node;
-        if (!(node = parse_subexpression(parser)))
+        if (!(node = parse_expression(parser)))
             break;
 
         out_nodes[i] = node;
diff --git a/ps_graph.h b/ps_graph.h
index 92774ae..2c0631f 100644
--- a/ps_graph.h
+++ b/ps_graph.h
@@ -9,6 +9,6 @@ struct graph_range {
 	double ymin, ymax;
 };
 
-extern void ps_generate_graph(FILE *file, const struct expr_node *node, const struct graph_range *range, const char *function);
+void ps_generate_graph(FILE *file, const struct expr_node *node, const struct graph_range *range, const char *function);
 
 #endif
\ No newline at end of file