“…These questions were addressed by the second author and various co-authors in a series of papers on unifying functional interpretations. Starting with a unification of interpretations of intuitionistic logic [21], which was followed by various analysis of functional interpretations within the finer setting of linear logic [13,22,23,24], a proposal on how functional interpretations could actually be combined in the so-called hybrid functional interpretations [17,25], and the inclusion of truth variants in the unification [15].…”