diff --git a/utshell-0.5/r_expr/src/lib.rs b/utshell-0.5/r_expr/src/lib.rs
index a640b557acc9f81bded122288a970c270c6c7b60..82e3ac4f074e861b4c5de77e3a327f6ace1e5dca 100644
--- a/utshell-0.5/r_expr/src/lib.rs
+++ b/utshell-0.5/r_expr/src/lib.rs
@@ -1235,4 +1235,26 @@ unsafe extern "C" fn popexp() {
         b"../expr.c\0" as *const u8 as *const libc::c_char,
         299 as libc::c_int,
     );
+}
+
+#[no_mangle]
+unsafe extern "C" fn _is_arithop(mut c: libc::c_int) -> libc::c_int {
+    match c as u8 as char {
+        '=' | '>' | '<' | '+' | '-' | '*' | '/' | '%' | '!' | '(' | ')' | '&' | '|' | '^' | '~' => {
+            return 1 as libc::c_int;
+        }
+        '?' | ':' | ',' => return 1 as libc::c_int,
+        _ => return 0 as libc::c_int,
+    };
+}
+
+#[no_mangle]
+unsafe extern "C" fn _is_multiop(mut c: libc::c_int) -> libc::c_int {
+    match c {
+        EQEQ | NEQ | LEQ | GEQ | LAND | LOR | LSH | RSH | OP_ASSIGN | COND | POWER | PREINC
+        | PREDEC | POSTINC | POSTDEC => {
+            return 1 as libc::c_int;
+        }
+        _ => return 0 as libc::c_int,
+    };
 }
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