problem: !SequentialCoupling
  description: Test of boundary conditions for transport
  mesh:
    mesh_file: ./input/mesh.msh
  primary_equation: !Steady_MH
    input_fields:
      - r_set: BOUNDARY
        bc_type: dirichlet
        bc_pressure: !FieldFormula
          value: (1-x)/10
    output:
      output_stream: 
        file: ./flow.pvd
        format: !vtk
          variant: ascii
        name: flow_output_stream
      output_fields:
        - pressure_p0
        - velocity_p0
    balance: true
    solver: !Petsc &anchor3
      a_tol: 1.0e-12
      r_tol: 1.0e-12
  secondary_equation: !SoluteTransport_DG
    input_fields:
      - region: domain
        diff_m: 0.01
        sources_density: 0
      - region: .left
        bc_type: dirichlet
        bc_conc: !FieldFormula
          value: 2-((y-0.5)*2)^8
      - region: .right
        bc_type: dirichlet
        bc_conc: !FieldFormula
          value: ((y-0.5)*2)^8
      - region: .top
        bc_type: dirichlet
        bc_conc: 1
      - region: .bottom
        bc_type: dirichlet
        bc_conc: 1
    output_stream: 
      file: ./transport.pvd
      format: !vtk
        variant: ascii
      time_step: 1
      name: transport_output_stream
    substances:
      - tracer
    time:
      end_time: 10
    balance:
      cumulative: true
    solver: *anchor3