Confusion about elisp symbols and defuns

[dieter@duenenhof-wilhelm.de (H. Dieter Wilhelm)]

Hello (),

Calc checks in calc-var-value if variables are bound.  This works for
examplwe with the variable symbol `g'

(calc-var-value 'g)
nil

but bombs for the variable `v'

(calc-var-value 'v)
=> error

The reason seems to me that somehow over the parameter name (v) of the
defun the symbol `v' becomes bound.  (Excuse my layman interpretation.)

(makunbound 'g)
g

(makunbound 'v)
v

(symbolp 'v)
t

(boundp 'v)
nil

(boundp 'g)
nil

(defun bla (v)
  (boundp v))
bla

(bla 'g)
nil

(bla 'v)
t

(defun foo (v)
  (makunbound v)
  (boundp v))
foo

(foo 'g)
nil

(foo 'v)
=> error signal


How would you change the calc-var-value to avoid this trap?

Thanks for any enlightenment

       Dieter
-- 
Best wishes
H. Dieter Wilhelm
Darmstadt, Germany