[求助] 求助程序，defined recursively

program main
    USE var
    implicit none
    !subroutine mark
 xc(1,1)=(Lx/2.0+L/2.0*cos(angle))/dx;
 xc(1,2)=(Ly-20.0*D+L/2.0*sin(angle))/dx;
 xc(2,1)=(Lx/2.0-L/2.0*cos(angle))/dx;
 xc(2,2)=(Ly-20.0*D-L/2.0*sin(angle))/dx;
beta=Gr*mv*mv/(G*D**3*(Tw(2)-T_f));
write (*,'(1x,"tao=",f12.6,2x,"ny=",I4)') tao,ny
call initialize
!call ini_T
do step=1,stepmax
    call mark
    call calculate_u_p
    call particle_boundary
    call around_boundary
    !call evolution
    call collision
    call second_forcing
    call stream_
    
    !-----------T----------
    !call evolve_T
    !call save_fx_fy
    call particle_move_evolvement
    !call shift_domain
enddo
    
!call data_deal
end program main