and
 Determines which solver will be used in forward simulation, see
Linear system equations solvers
, default is .
The default preconditioner is . 
 Specifies the parameters for the selected solver:
Number of maximal allowed iterations needed to solve one linear system
of equations ( “inner iterations” ), integer number,
default is 1000 (iterative solvers only).
Number of maximal allowed recomputations of the coefficients of
the system of equations for nonlinear problems. This reconstruction
of the matrix together with the solving is called an
“outer iteration”, integer number, default is 500.
Desired accuracy of the computation; must be a small real number,
default is 1e12.
At each “outer iteration” the solver is asked
to perform inner iterations until the actual residuum has got smaller
than the residuum of the previous outer iteration divided by this
factor, default is 10 times.
At each iteration, when a new value is computed, only this fraction from
the variation is taken. Real number between 0 and 1, default is 0.5.
For timedependent computations choose a value closer to 1. For pseudostationary computations choose a value closer to 0.

 Miscellaneous numerical options:
Turns on the adjustment of the phase boundary in a two phase material
when calculating temperature. The vertices next to the phase boundary
are moved in order to match with the melting isothermal.(default: false)
If selected (default), latent heat is released in the mushy zone around the phase change temperature, as described in the materials dialog section. In certain cases in conjunction with phase tracking this turns out to be unstable. If you unselect the enthalpy method here, latent heat will be released only in the control volumes around vertices tagged as lying on the interface, which sometimes is more stable. Attention: While using the enthalpy metod the interface velocities sign is positive if growth is upwards, and viceversa, with this method, a positive value means solidification, a negative one melting!
