pro-sumti: in the second half of a sumti forethought connective expression, refers to the first half.
For example, in "ge X gi lo co'e be gibu", gibu refers to X. In case of nesting, the innermost connective is targeted, unless a subscript specifies otherwise: in "ge X gi tu'a ga Y gi gibu", gibu refers to Y. "gibu xi re" may be used to refer to the second-innermost referent, X. See nu bu.