Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:Wadge has proposed in [112] a fragment of higher-order Horn logic called “definitional programs” as a meta-programming language “based on Church’s Simple Theory of Types” [112], that is, the Simply Typed Lambda Calculus or λ→ [28, 6].
Category: