paper Relates Observational equivalence, see A Robust Graph-Based Approach to Observational Equivalence. James Hiram Morris Jr. Lambda-calculus models of programming languages. PhD thesis, Massachusetts Institute of Technology, 1969
paper Relates Observational equivalence, see A Robust Graph-Based Approach to Observational Equivalence. James Hiram Morris Jr. Lambda-calculus models of programming languages. PhD thesis, Massachusetts Institute of Technology, 1969