unprotect
-- remove protection
of identifiersunprotect
(x)
removes any write protection
of the identifier x
.
unprotect(x)
x |
- | an identifier |
the previous protection level of x
: either Error or Warning or None (see protect
).
unprotect(
x)
is equivalent to protect
(x,
None)
.unprotect
does not evaluate its argument. Cf.
example 2.unprotect
allows to assign values to system
functions:
>> unprotect(sign): sign(x) := 1
1
However, we strongly advise not to change identifiers protected by the system. We undo the previous assignment:
>> delete sign(x): protect(sign, Error):
unprotect
does not evaluate its argument.
Here the identifier x
is unprotected and not its value
y
:
>> x := y: protect(y): unprotect(x): y := 1
Warning: protected variable y overwritten 1
>> unprotect(y): delete x, y: