Program sfstack3 | OpenMP stack on axis 1,2 or 3 
[SYNOPSIS]
sfstack3 < Fi.rsf > Fo.rsf verb=n axis=2 verb=y nbuf=1
[PARAMETERS]
int     | axis | =2 |   | 	stack axis 
int     | nbuf | =1 |   | 	buffer size 
bool    | verb | =y |  [y/n] | 	verbosity flag 
[DIRECTORY]
user/psava
