diff --git a/include/picrin.h b/include/picrin.h
index 6a7a946e..f3d54c10 100644
--- a/include/picrin.h
+++ b/include/picrin.h
@@ -71,6 +71,9 @@ typedef struct {
   pic_sym sQUASIQUOTE, sUNQUOTE, sUNQUOTE_SPLICING;
   pic_sym sDEFINE_SYNTAX, sDEFINE_MACRO;
   pic_sym sDEFINE_LIBRARY, sIMPORT, sEXPORT;
+  pic_sym sCONS, sCAR, sCDR, sNILP;
+  pic_sym sADD, sSUB, sMUL, sDIV;
+  pic_sym sEQ, sLT, sLE, sGT, sGE;
 
   struct xhash *sym_tbl;
   const char **sym_pool;
diff --git a/src/state.c b/src/state.c
index a7b987e8..a312ae2a 100644
--- a/src/state.c
+++ b/src/state.c
@@ -98,6 +98,19 @@ pic_open(int argc, char *argv[], char **envp)
   register_core_symbol(pic, sDEFINE_LIBRARY, "define-library");
   register_core_symbol(pic, sIMPORT, "import");
   register_core_symbol(pic, sEXPORT, "export");
+  register_core_symbol(pic, sCONS, "cons");
+  register_core_symbol(pic, sCAR, "car");
+  register_core_symbol(pic, sCDR, "cdr");
+  register_core_symbol(pic, sNILP, "null?");
+  register_core_symbol(pic, sADD, "+");
+  register_core_symbol(pic, sSUB, "-");
+  register_core_symbol(pic, sMUL, "*");
+  register_core_symbol(pic, sDIV, "/");
+  register_core_symbol(pic, sEQ, "=");
+  register_core_symbol(pic, sLT, "<");
+  register_core_symbol(pic, sLE, "<=");
+  register_core_symbol(pic, sGT, ">");
+  register_core_symbol(pic, sGE, ">=");
   pic_gc_arena_restore(pic, ai);
 
   pic_init_core(pic);