+copy(1) ----> 1
+copy(1.0) ----> 1.0
+copy("abc") ----> "abc"
+copy('aabbcc') ----> 'abc'
+copy(main) ----> procedure main
+copy([1,2,3]) ----> list(3)
+copy(table(0)) ----> table(0)
+copy() ----> &null
+copy(&input) ----> &input
+w := copy(write) ----> function write
+function write
+w(image(w)) ----> "function write"
+copy(array()) ----> record array(7)
+copy := copy(copy) ----> function copy
+x := copy(array) ----> record constructor array
+x := x(1,2,3,4,5,6,7) ----> record array(7)
+x[-4] ----> 4
+v := copy(c) ----> &null
+Run-time error 106 at line 26 in std24.icn
+procedure or integer expected
+offending value: &null