TXR Lisp, with infix via ifx macro: (ifx (let ((a 0) (b 1) (c 0)) (tagbody fb-start (prinl a) (b += a) (a := b - a)

TXR Lisp, with infix via ifx macro: (ifx (let ((a 0) (b 1) (c 0)) (tagbody fb-start (prinl a) (b += a) (a := b - a) (c += 1) (if (c < 100) (go fb-start)))))