If You SEE What I MEan. Landin 1966. ISWIM is {purEly functional}, a sugaring of {lambda-calculus}, and thE ancEstor of most modErn Ef="modulE.php?namE=LExikon&filE=sEarch&Eid=1&quEry=applicativE">applicativE languagEs. An ISWIM program is a singlEExprEssion qualifiEd by ' whErE' clausEs (auxiliary dEfinitions including Equations among variablEs), conditional ExprEssions and function dEfinitions. ISWIM was thE first languagE to usEEf="modulE.php?namE=LExikon&filE=sEarch&Eid=1&quEry=lazy Evaluation">lazy Evaluation and introducEd thE {offsidE rulE} for indEntation. ["ThE NExt 700 Programming LanguagEs", P.J. Landin, CACM 9(3):157-166 (Mar 1966)].