where

N_b,fi,Rd is the design buckling resistance of a compression member in fire design situation according to 6.2.2 (flexural buckling around main or geometric axis of symetry),

M_b,fi,Rd is the lateral-torsional bending moment resistance in fire design situation according to 6.2.4

M_c,fi,Rd is bending moment resistance in fire design situation according to 6.1.4.1, if lateral-torsional bucking doesn’t appears

M_y,Ed and M_z,Ed including the effects of shift of neutral axis, if relevant.

where

N_fi,Rd is the design resistance of a cross-section for uniform tension in fire design situation