This book constitutes the thoroughly refereed post-conference proceedings of the 12th Brazilian
Symposium on Formal Methods SBMF 2009 held in Gramado Brazil in August 2009 -- co-located
with SAST 2009 the Brazilian Workshop on Systematic and Automated Software Testing. The 20
revised full papers presented together with 3 invited papers were carefully selected from
numerous submissions during two rounds of reviewing and improvement. The papers are devoted to
the dissemination of the development and use of formal methods for the design and verification
of computational systems. The symposium provided an opportunity for researchers with a broad
range of interests in formal methods for developing computing systems and software to discuss
recent developments in this field.
