## APL Hacking: Project Euler Daily (#2)

For this one, I could not come up with a solution that did not have a loop in it, but I tried to make that loop as simple as possible.Problem #2:

∇R←PETWO;X;⎕IO ⎕IO←1 ⍝ Find the sum of all even fibonacci numbers < 4,000,000 X←0 1 :Repeat X←X,X[⍴X]+X[(⍴X)-1] :Until X[⍴X]>4000000 R←+/(0=2|X)/X ∇