Program sfaimplfd2 | Implicit solution of 2-D acoustic wave equation. 
[SYNOPSIS]
sfaimplfd2 < vel.rsf > usol.rsf src=src.rsf niter=10 fourth=y
[PARAMETERS]
bool    | fourth | =y |  [y/n] | 	Higher order flag 
int     | niter | =10 |   | 	Number of solver iterations 
string  | src | = |   | 	Source wavelet (auxiliary input file name)
[DIRECTORY]
user/petsc
