YES

Problem:
 a() -> c()
 f(f(c())) -> h(a(),h(h(c(),c()),b()))
 f(f(a())) -> b()
 b() -> f(f(b()))

Proof:
 Uncurry Processor:
  a() -> c()
  f5(f(),f5(f(),c())) -> f5(f5(h(),a()),f5(f5(h(),f5(f5(h(),c()),c())),b()))
  f5(f(),f5(f(),a())) -> b()
  b() -> f5(f(),f5(f(),b()))
  Ground Confluence Processor:
   UNC by decision procedure.