I'am happy to know that that stuff can have closures but I'm not smart enough to implement them. I am a retired architect and not a professional coder. Meanwhil

I'am happy to know that that stuff can have closures but I'm not smart enough to implement them. I am a retired architect and not a professional coder. Meanwhile this is the workaround I use. For instance, the area of any triangle of sides[a,b,c] is given by the formula area = √s*(s-a)*(s-b)*(s-c) where s = (a+b+c)/2 If the intermediate variable s is provided alone in an IIFE, like this : {def area1 {lambda {:a :b :c} {{lambda {:s} // it's an IIFE where :s will be replaced ... {sqrt {* :s {- :s :a} {- :s :b} {- :s :c}}} // ... here ... } {/ {+ :a :b :c} 2}}}} // ... by this value computed once -> area1 {area1 3 4 5} -> NaN // Not a Number it doesn't work, simply because [:a :b :c] are not in the inner function's arguments list and a function knows nothing about its context. It is necessary to manually add the arguments of the calling function {def area2 {lambda {:a :b :c} {{lambda {:a :b :c :s} // :a :b :c are redefined ... {sqrt {* :s {- :s :a} {- :s :b} {- :s :c}}} } :a :b :c // ... get values from the outer func ... {/ {+ :a :b :c} 2}} // ... and from the new computed value }} -> area2 {area2 3 4 5} -> 6 For information lambdas are implemented at the beginning of this javascript file http://lambdaway.free.fr/lambdawalks/meca/JS.js http://lambdaway.free.fr/lambdawalks/meca/JS.js I wouldn't want to complicate the code too much and especially lose the automatic partial application, which seems to me incompatible with closures. Thank you for your kind remarks