  A variety of logical frameworks support the use of higher-order abstract
syntax (HOAS) in representing formal systems. Although these systems seem
superficially the same, they differ in a variety of ways; for example, how they
handle a context of assumptions and which theorems about a given formal system
can be concisely expressed and proved. Our contributions in this paper are
three-fold: 1) we develop a common infrastructure for representing benchmarks
for systems supporting reasoning with binders, 2) we present several concrete
benchmarks, which highlight a variety of different aspects of reasoning within
a context of assumptions, and 3) we design an open repository ORBI, (Open
challenge problem Repository for systems supporting reasoning with BInders).
Our work sets the stage for providing a basis for qualitative comparison of
different systems. This allows us to review and survey the state of the art,
which we do in great detail for four systems in Part 2 of this paper (Felty et
al, 2015). It also allows us to outline future fundamental research questions
regarding the design and implementation of meta-reasoning systems.
