https://manpages.ubuntu.com/manpages/focal/man3/pclarfb.3.html
Ubuntu Manpage: PCLARFB - applie a complex block reflector Q or its conjugate transpose Q**H to a...
applie a complex block reflector Q or its conjugate transpose Q**H to a complex M-by-N distributed matrix sub( C ) denoting C(IC:IC+M-1,JC:JC+N-1), from the...
block reflectorconjugate transposeubuntumanpagecomplex