  The UITP workshop series brings together researchers interested in designing,
developing and evaluating user interfaces for automated reasoning tools, such
as interactive proof assistants, automated theorem provers, model finders,
tools for formal methods, and tools for visualising and manipulating logical
formulas and proofs. The twelth edition of UITP took place in Coimbra,
Portugal, and was part of the International Joint Conference on Automated
Reasoning (IJCAR'16). The workshop consisted of an invited talk, six
presentations of submitted papers and lively hands-on session for reasoning
tools and their user-interface. These post-proceedings contain four contributed
papers accepted for publication after a second round of reviewing after the
workshop as well as the invited paper.
