Equation Icon  (A ) f (R ) = R − μRc(R ∕Rc )p with 0 < p < 1, μ,Rc > 0, (1.4.51 ) (R ∕Rc )2n (B ) f(R ) = R − μRc -------2n----- with n,μ, Rc > 0, (1.4.52 ) (R[ ∕Rc ) + 1 ] (C ) f (R ) = R − μR 1 − (1 + R2∕R2 )−n with n, μ,R > 0, (1.4.53 ) c c c (D ) f (R ) = R − μRctanh (R ∕Rc) with μ, Rc > 0. (1.4.54 )