Incorrect parsing of floating point numbers without a leading zero

[ptdecker]

The parenthesis are not balancing in:

(define (good-enough? guess x) (< (abs (- (square guess) x)) .001))

But it works in:

(define (good-enough? guess x) (< (abs (- (square guess) x)) 0.001))

Because the floating point number is not being parsed correctly

The workaround for this is to always add a leading zero for floating point constants