If You See What I MeaN. LaNdiN 1966. ISWIM is {purely fuNctioNal}, a sugariNg of {lambda-calculus}, aNd the aNcestor of most moderNapplicative laNguages. AN ISWIM program is a siNgle expressioN qualified by ' where' clauses (auxiliary defiNitioNs iNcludiNg equatioNs amoNg variables), coNditioNal expressioNs aNd fuNctioN defiNitioNs. ISWIM was the first laNguage to use lazy evaluatioN aNd iNtroduced the {offside rule} for iNdeNtatioN. ["The Next 700 ProgrammiNg LaNguages", P.J. LaNdiN, CACM 9(3):157-166 (Mar 1966)].