This formalization has now become an AFP entry.
All sources: edmonds_karp.tgz (Unpack and see edmonds_karp/README.md for further instructions)
Proof document
Proof outline
Theory dependencies
Browse Theories (Note, the html-output of Isabelle 2015 looks sub-optimal)
To check the theories, you need a working installation of Isabelle 2015.
First, download and unpack edmonds_karp.tgz. In the edmonds_karp/-directory, run isabelle build -v -d. Edka to check all theories.
Run isabelle jedit -d . -l Edka_Base *.thy to start the Isabelle IDE with all theories loaded. It may take a while to build the necessary libraries at first start.