YES

(format LCTRS :logic QF_LIA)
(fun f1 1 :sort (Int Int))
(fun u_5 1 :sort (Int Int))
(fun u_8 1 :sort (Int Int))

(rule (u_8 w_3_0) w_3_0 :vars ((w_3_0 Int)))
(rule (u_5 w_2_1) (u_8 (f1 w_2_1)) :vars ((w_2_1 Int)))
(rule (f1 a_2) (u_5 (f1 (+ a_2 11))) :guard (<= a_2 100) :vars ((a_2 Int)))
(rule (f1 a_3) (- a_3 10) :guard (> a_3 100) :vars ((a_3 Int)))

Confluent by Orthogonality with proof:
no critical pairs

Elapsed Time:  34.76 ms