loop through vt.
To process each element of a list of things. "Hold on, I've
got to loop through my paper mail." Derives from the
computer-language notion of an iterative loop; compare `cdr down'
(under cdr), which is less common among
C and Unix programmers. ITS hackers used to say `IRP over' after
an obscure pseudo-op in the MIDAS PDP-10 assembler (the same IRP
op can nowadays be found in Microsoft's assembler).