# Declarative Commands

These commands are used to define problem parameters. They are order-independent and may be placed anywhere in the file relative to each other.

For example, the NODAL_BOUNDARY_CONDITION command may be specified before or after the COORDINATE command, even though the former depends on the latter. However, the placement of these commands relative to the functional commands is important. For example in:
RESTART {
from_problem = "channel"
}
NODAL_INITIAL_CONDITION( temperature ) {
default_value = 20
}
the problem starts with temperature values of 20 degrees, whereas in
NODAL_INITIAL_CONDITION( temperature ) {
default_value = 20
}
RESTART {
from_problem = "channel"
}

the problem starts with the temperature values given in the restart file.