This book constitutes the proceedings of the 21st International Conference on Foundations of
Software Science and Computational Structures FOSSACS 2018 which took place in Thessaloniki
Greece in April 2018 held as part of the European Joint Conference on Theory and Practice of
Software ETAPS 2018.The 31 papers presented in this volume were carefully reviewed and
selected from 103 submissions. The papers are organized in topical sections named: semantics
linearity concurrency lambda-calculi and types category theory and quantum control
quantitative models logics and equational theories and graphs and automata.
