diff --git a/src/modal.c b/src/modal.c
index 19e19f3..efa3e57 100644
--- a/src/modal.c
+++ b/src/modal.c
@@ -104,7 +104,7 @@ write_tail(char *s)
 static int
 apply_rule(Rule *r, char *s)
 {
-	unsigned int i, rid;
+	unsigned char i, rid;
 	char c, *a = r->a, *b = r->b, *origin = dst_, *reg;
 	/* phase: clean regs */
 	if(rmax) {
@@ -152,28 +152,23 @@ apply_rule(Rule *r, char *s)
 }
 
 static char *
-compile_rule(Rule *r, int id, char *src)
+parse_frag(Rule *r, int side, char *src)
 {
-	char c, *cap;
 	int wrapped;
-	r->id = id, r->a = &empty, r->b = ∅
-	/* phase: compile left */
+	char c, *cap;
+	if(side)
+		r->b = ∅
+	else
+		r->a = ∅
 	while((c = *src) && c == ' ') src++;
 	if(c == ')' || (c == '<' && src[1] == '>')) return src;
-	r->a = dict_, cap = walk(src), wrapped = c == '(';
+	if(side)
+		r->b = dict_;
+	else
+		r->a = dict_;
+	cap = walk(src), wrapped = c == '(';
 	if(wrapped) src++, cap--;
-	while(src < cap) {
-		c = *src, *dict_++ = *src++;
-	}
-	src += wrapped, *dict_++ = 0;
-	/* phase: compile right */
-	while((c = *src) && c == ' ') src++;
-	if(c == ')' || (c == '<' && src[1] == '>')) return src;
-	r->b = dict_, cap = walk(src), wrapped = c == '(';
-	if(wrapped) src++, cap--;
-	while(src < cap) {
-		c = *src, *dict_++ = *src++;
-	}
+	while(src < cap) c = *src, *dict_++ = *src++;
 	src += wrapped, *dict_++ = 0;
 	return src;
 }
@@ -203,8 +198,8 @@ rewrite(void)
 			Rule *r = NULL;
 			/* phase: define */
 			if(c == '<' && s[1] == '>') {
-				r = rules_;
-				s = compile_rule(r, rules_ - rules - 1, s + 2);
+				r = rules_, r->id = rules_ - rules - 1;
+				s = parse_frag(r, 1, parse_frag(r, 0, s + 2));
 				if(*r->a) {
 					if(!quiet && r->a)
 						printf("<> (%s) (%s)\n", r->a, r->b);
@@ -226,7 +221,10 @@ rewrite(void)
 			}
 			/* phase: lambda */
 			if(c == '?' && s[1] == '(') {
-				cap = walk(s + 1), compile_rule(&lambda, -1, s + 2), s = cap;
+				cap = walk(s + 1);
+				r = &lambda, r->id = -1;
+				parse_frag(r, 1, parse_frag(r, 0, s + 2));
+				s = cap;
 				while(*s == ' ') s++;
 				if(!apply_rule(&lambda, s)) write_tail(s);
 				return 1;