Global scope confusion again

a is a global variable in the REPL and must be annotated inside the loop as such, to avoid this, insert your code inside a function. See this discussion for more information: REPL and for loops (scope behavior change).

julia> function test()
           a = 1.0
           b = 1.0
           e = 0.1
           for i in 1:5
               x = a - e*b
               y = b + e*a
               println(i," “,x,” ",y)
               a = x
               b = y
           end
       end
test (generic function with 1 method)

julia> test()
1 “,x,” 1.1
2 “,x,” 1.1900000000000002
3 “,x,” 1.2690000000000001
4 “,x,” 1.3361
5 “,x,” 1.3905100000000001