diff --git a/number.c b/number.c
new file mode 100644
index 0000000..fe194cd
--- /dev/null
+++ b/number.c
@@ -0,0 +1,226 @@
+typedef struct Number{
+	enum{
+		NUM_INT,
+		NUM_DOUBLE
+	}type; // 0 -> int   1 -> double
+	union{
+		double double_val;
+		int int_val;
+	};
+} Number;
+Number addNumber(Number a,Number b){
+	if (a.type==a.NUM_INT){
+		if (b.type==b.NUM_INT){
+			Number c;
+			c.type=c.NUM_INT;
+			c.int_val=a.int_val+b.int_val;
+			return c;
+		}else{ //NUM_DOUBLE
+			Number c;
+			c.type=c.NUM_DOUBLE;
+			c.double_val=a.int_val+b.double_val;
+			return c;
+		}
+	}else{ //NUM_DOUBLE
+		if (b.type==b.NUM_INT){
+			Number c;
+			c.type=c.NUM_DOUBLE;
+			c.int_val=a.double_val+b.int_val;
+			return c;
+		}else{ //NUM_DOUBLE
+			Number c;
+			c.type=c.NUM_DOUBLE;
+			c.double_val=a.double_val+b.double_val;
+			return c;
+		}
+	}
+}
+Number subNumber(Number a,Number b){
+	if (a.type==a.NUM_INT){
+		if (b.type==b.NUM_INT){
+			Number c;
+			c.type=c.NUM_INT;
+			c.int_val=a.int_val-b.int_val;
+			return c;
+		}else{ //NUM_DOUBLE
+			Number c;
+			c.type=c.NUM_DOUBLE;
+			c.double_val=a.int_val-b.double_val;
+			return c;
+		}
+	}else{ //NUM_DOUBLE
+		if (b.type==b.NUM_INT){
+			Number c;
+			c.type=c.NUM_DOUBLE;
+			c.int_val=a.double_val-b.int_val;
+			return c;
+		}else{ //NUM_DOUBLE
+			Number c;
+			c.type=c.NUM_DOUBLE;
+			c.double_val=a.double_val-b.double_val;
+			return c;
+		}
+	}
+}
+Number mulNumber(Number a,Number b){
+	if (a.type==a.NUM_INT){
+		if (b.type==b.NUM_INT){
+			Number c;
+			c.type=c.NUM_INT;
+			c.int_val=a.int_val*b.int_val;
+			return c;
+		}else{ //NUM_DOUBLE
+			Number c;
+			c.type=c.NUM_DOUBLE;
+			c.double_val=a.int_val*b.double_val;
+			return c;
+		}
+	}else{ //NUM_DOUBLE
+		if (b.type==b.NUM_INT){
+			Number c;
+			c.type=c.NUM_DOUBLE;
+			c.int_val=a.double_val*b.int_val;
+			return c;
+		}else{ //NUM_DOUBLE
+			Number c;
+			c.type=c.NUM_DOUBLE;
+			c.double_val=a.double_val*b.double_val;
+			return c;
+		}
+	}
+}
+Number divNumber(Number a,Number b,const char ** msg){
+	if (a.type==a.NUM_INT){
+		if (b.type==b.NUM_INT){
+			Number c;
+			if (b.int_val==0){
+				msg[0]="divided by zero";
+			}else{
+				c.type=c.NUM_INT;
+				c.int_val=a.int_val/b.int_val;
+			}
+			return c;
+		}else{ //NUM_DOUBLE
+			Number c;
+			c.type=c.NUM_DOUBLE;
+			c.double_val=a.int_val/b.double_val;
+			return c;
+		}
+	}else{ //NUM_DOUBLE
+		if (b.type==b.NUM_INT){
+			Number c;
+			if (b.int_val==0){
+				msg[0]="divided by zero";
+			}else{
+				c.type=c.NUM_DOUBLE;
+				c.int_val=a.double_val/b.int_val;
+			}
+			return c;
+		}else{ //NUM_DOUBLE
+			Number c;
+			c.type=c.NUM_DOUBLE;
+			c.double_val=a.double_val/b.double_val;
+			return c;
+		}
+	}
+}
+Number modNumber(Number a,Number b,const char ** msg){
+	Number c;
+	if (a.type!=a.NUM_INT || b.type!=b.NUM_INT){
+		msg[0]="cannot use non-integer value in mod";
+	}else{
+		c.type=c.NUM_INT;
+		c.int_val=a.int_val%b.int_val;
+	}
+	return c;
+}
+bool leNumber(Number a,Number b){
+	if (a.type==a.NUM_INT){
+		if (b.type==b.NUM_INT){
+			return a.int_val<b.int_val;
+		}else{ //NUM_DOUBLE
+			return a.int_val<b.double_val;
+		}
+	}else{ //NUM_DOUBLE
+		if (b.type==b.NUM_INT){
+			return a.double_val<b.int_val;
+		}else{ //NUM_DOUBLE
+			return a.double_val<b.double_val;
+		}
+	}
+}
+bool geNumber(Number a,Number b){
+	if (a.type==a.NUM_INT){
+		if (b.type==b.NUM_INT){
+			return a.int_val>b.int_val;
+		}else{ //NUM_DOUBLE
+			return a.int_val>b.double_val;
+		}
+	}else{ //NUM_DOUBLE
+		if (b.type==b.NUM_INT){
+			return a.double_val>b.int_val;
+		}else{ //NUM_DOUBLE
+			return a.double_val>b.double_val;
+		}
+	}
+}
+bool nleNumber(Number a,Number b){
+	if (a.type==a.NUM_INT){
+		if (b.type==b.NUM_INT){
+			return a.int_val>=b.int_val;
+		}else{ //NUM_DOUBLE
+			return a.int_val>=b.double_val;
+		}
+	}else{ //NUM_DOUBLE
+		if (b.type==b.NUM_INT){
+			return a.double_val>=b.int_val;
+		}else{ //NUM_DOUBLE
+			return a.double_val>=b.double_val;
+		}
+	}
+}
+bool ngeNumber(Number a,Number b){
+	if (a.type==a.NUM_INT){
+		if (b.type==b.NUM_INT){
+			return a.int_val<=b.int_val;
+		}else{ //NUM_DOUBLE
+			return a.int_val<=b.double_val;
+		}
+	}else{ //NUM_DOUBLE
+		if (b.type==b.NUM_INT){
+			return a.double_val<=b.int_val;
+		}else{ //NUM_DOUBLE
+			return a.double_val<=b.double_val;
+		}
+	}
+}
+bool eqNumber(Number a,Number b){
+	if (a.type==a.NUM_INT){
+		if (b.type==b.NUM_INT){
+			return a.int_val==b.int_val;
+		}else{ //NUM_DOUBLE
+			return a.int_val==b.double_val;
+		}
+	}else{ //NUM_DOUBLE
+		if (b.type==b.NUM_INT){
+			return a.double_val==b.int_val;
+		}else{ //NUM_DOUBLE
+			return a.double_val==b.double_val;
+		}
+	}
+}
+bool neqNumber(Number a,Number b){
+	if (a.type==a.NUM_INT){
+		if (b.type==b.NUM_INT){
+			return a.int_val!=b.int_val;
+		}else{ //NUM_DOUBLE
+			return a.int_val!=b.double_val;
+		}
+	}else{ //NUM_DOUBLE
+		if (b.type==b.NUM_INT){
+			return a.double_val!=b.int_val;
+		}else{ //NUM_DOUBLE
+			return a.double_val!=b.double_val;
+		}
+	}
+}
diff --git a/simpleruntime.c b/simpleruntime.c
index b4590dc..3a34d40 100644
--- a/simpleruntime.c
+++ b/simpleruntime.c
@@ -1,232 +1,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <math.h>
-typedef struct Number{
-	enum{
-		NUM_INT,
-		NUM_DOUBLE
-	}type; // 0 -> int   1 -> double
-	union{
-		double double_val;
-		int int_val;
-	};
-} Number;
-Number addNumber(Number a,Number b){
-	if (a.type==a.NUM_INT){
-		if (b.type==b.NUM_INT){
-			Number c;
-			c.type=c.NUM_INT;
-			c.int_val=a.int_val+b.int_val;
-			return c;
-		}else{ //NUM_DOUBLE
-			Number c;
-			c.type=c.NUM_DOUBLE;
-			c.double_val=a.int_val+b.double_val;
-			return c;
-		}
-	}else{ //NUM_DOUBLE
-		if (b.type==b.NUM_INT){
-			Number c;
-			c.type=c.NUM_DOUBLE;
-			c.int_val=a.double_val+b.int_val;
-			return c;
-		}else{ //NUM_DOUBLE
-			Number c;
-			c.type=c.NUM_DOUBLE;
-			c.double_val=a.double_val+b.double_val;
-			return c;
-		}
-	}
-}
-Number subNumber(Number a,Number b){
-	if (a.type==a.NUM_INT){
-		if (b.type==b.NUM_INT){
-			Number c;
-			c.type=c.NUM_INT;
-			c.int_val=a.int_val-b.int_val;
-			return c;
-		}else{ //NUM_DOUBLE
-			Number c;
-			c.type=c.NUM_DOUBLE;
-			c.double_val=a.int_val-b.double_val;
-			return c;
-		}
-	}else{ //NUM_DOUBLE
-		if (b.type==b.NUM_INT){
-			Number c;
-			c.type=c.NUM_DOUBLE;
-			c.int_val=a.double_val-b.int_val;
-			return c;
-		}else{ //NUM_DOUBLE
-			Number c;
-			c.type=c.NUM_DOUBLE;
-			c.double_val=a.double_val-b.double_val;
-			return c;
-		}
-	}
-}
-Number mulNumber(Number a,Number b){
-	if (a.type==a.NUM_INT){
-		if (b.type==b.NUM_INT){
-			Number c;
-			c.type=c.NUM_INT;
-			c.int_val=a.int_val*b.int_val;
-			return c;
-		}else{ //NUM_DOUBLE
-			Number c;
-			c.type=c.NUM_DOUBLE;
-			c.double_val=a.int_val*b.double_val;
-			return c;
-		}
-	}else{ //NUM_DOUBLE
-		if (b.type==b.NUM_INT){
-			Number c;
-			c.type=c.NUM_DOUBLE;
-			c.int_val=a.double_val*b.int_val;
-			return c;
-		}else{ //NUM_DOUBLE
-			Number c;
-			c.type=c.NUM_DOUBLE;
-			c.double_val=a.double_val*b.double_val;
-			return c;
-		}
-	}
-}
-Number divNumber(Number a,Number b,const char ** msg){
-	if (a.type==a.NUM_INT){
-		if (b.type==b.NUM_INT){
-			Number c;
-			if (b.int_val==0){
-				msg[0]="divided by zero";
-			}else{
-				c.type=c.NUM_INT;
-				c.int_val=a.int_val/b.int_val;
-			}
-			return c;
-		}else{ //NUM_DOUBLE
-			Number c;
-			c.type=c.NUM_DOUBLE;
-			c.double_val=a.int_val/b.double_val;
-			return c;
-		}
-	}else{ //NUM_DOUBLE
-		if (b.type==b.NUM_INT){
-			Number c;
-			if (b.int_val==0){
-				msg[0]="divided by zero";
-			}else{
-				c.type=c.NUM_DOUBLE;
-				c.int_val=a.double_val/b.int_val;
-			}
-			return c;
-		}else{ //NUM_DOUBLE
-			Number c;
-			c.type=c.NUM_DOUBLE;
-			c.double_val=a.double_val/b.double_val;
-			return c;
-		}
-	}
-}
-Number modNumber(Number a,Number b,const char ** msg){
-	Number c;
-	if (a.type!=a.NUM_INT || b.type!=b.NUM_INT){
-		msg[0]="cannot use non-integer value in mod";
-	}else{
-		c.type=c.NUM_INT;
-		c.int_val=a.int_val%b.int_val;
-	}
-	return c;
-}
-bool leNumber(Number a,Number b){
-	if (a.type==a.NUM_INT){
-		if (b.type==b.NUM_INT){
-			return a.int_val<b.int_val;
-		}else{ //NUM_DOUBLE
-			return a.int_val<b.double_val;
-		}
-	}else{ //NUM_DOUBLE
-		if (b.type==b.NUM_INT){
-			return a.double_val<b.int_val;
-		}else{ //NUM_DOUBLE
-			return a.double_val<b.double_val;
-		}
-	}
-}
-bool geNumber(Number a,Number b){
-	if (a.type==a.NUM_INT){
-		if (b.type==b.NUM_INT){
-			return a.int_val>b.int_val;
-		}else{ //NUM_DOUBLE
-			return a.int_val>b.double_val;
-		}
-	}else{ //NUM_DOUBLE
-		if (b.type==b.NUM_INT){
-			return a.double_val>b.int_val;
-		}else{ //NUM_DOUBLE
-			return a.double_val>b.double_val;
-		}
-	}
-}
-bool nleNumber(Number a,Number b){
-	if (a.type==a.NUM_INT){
-		if (b.type==b.NUM_INT){
-			return a.int_val>=b.int_val;
-		}else{ //NUM_DOUBLE
-			return a.int_val>=b.double_val;
-		}
-	}else{ //NUM_DOUBLE
-		if (b.type==b.NUM_INT){
-			return a.double_val>=b.int_val;
-		}else{ //NUM_DOUBLE
-			return a.double_val>=b.double_val;
-		}
-	}
-}
-bool ngeNumber(Number a,Number b){
-	if (a.type==a.NUM_INT){
-		if (b.type==b.NUM_INT){
-			return a.int_val<=b.int_val;
-		}else{ //NUM_DOUBLE
-			return a.int_val<=b.double_val;
-		}
-	}else{ //NUM_DOUBLE
-		if (b.type==b.NUM_INT){
-			return a.double_val<=b.int_val;
-		}else{ //NUM_DOUBLE
-			return a.double_val<=b.double_val;
-		}
-	}
-}
-bool eqNumber(Number a,Number b){
-	if (a.type==a.NUM_INT){
-		if (b.type==b.NUM_INT){
-			return a.int_val==b.int_val;
-		}else{ //NUM_DOUBLE
-			return a.int_val==b.double_val;
-		}
-	}else{ //NUM_DOUBLE
-		if (b.type==b.NUM_INT){
-			return a.double_val==b.int_val;
-		}else{ //NUM_DOUBLE
-			return a.double_val==b.double_val;
-		}
-	}
-}
-bool neqNumber(Number a,Number b){
-	if (a.type==a.NUM_INT){
-		if (b.type==b.NUM_INT){
-			return a.int_val!=b.int_val;
-		}else{ //NUM_DOUBLE
-			return a.int_val!=b.double_val;
-		}
-	}else{ //NUM_DOUBLE
-		if (b.type==b.NUM_INT){
-			return a.double_val!=b.int_val;
-		}else{ //NUM_DOUBLE
-			return a.double_val!=b.double_val;
-		}
-	}
-}
+
+#include "number.c"
 
 typedef struct VContext VContext; // map<int,LazyValue*>
 typedef struct Continuation Continuation;