Symbol 'abs' not declared as a variable

cvc4_string_errors_03.smt2

(set-logic QF_S)
(declare-const str_a String)
(declare-const int_b Int)
(declare-const int_c Int)
(declare-const str_d String)
(assert (= 
    (str.++ 
      (str.++ 
        str_d 
        str_a) 
      (str.replace "LLLLL" 
        "LL" 
        "LLLL")) 
    (str.++ 
      "L" 
      "LLLL")))
(assert (not (str.suffixof (str.replace "LLLLL" 
        "LL" 
        "LLLL") (str.++ 
        "L" 
        "LLLL"))))
(assert (< (- (str.indexof str_d "" 2) (+ int_b (+ 341 int_c))) 625))
(assert (and 
    (and 
      (not (>= 786 int_b)) 
      (str.contains (str.replace "LLLLL" 
          str_a 
          "L") "L")) 
    (and 
      (< 0 int_b) 
      (str.prefixof "" ""))))
(assert (str.suffixof str_a str_d))
(assert (>= (abs (str.indexof str_d "" 3)) (str.len str_a)))
(check-sat)

ERRORS:
(error "Parse Error: <shell>:1.15: Symbol 'abs' not declared as a variable")