GNU Emacs @value{EMACSVER}.
@end ifnotinfo
-Copyright @copyright{} 1990--1991, 2001--2013 Free Software Foundation, Inc.
+Copyright @copyright{} 1990--1991, 2001--2014 Free Software Foundation, Inc.
@quotation
Permission is granted to copy, distribute and/or modify this document
leaving the first, third, fourth, and so on; @kbd{M-3 M-@key{DEL}} deletes
the third stack element.
+The above commands do not depend on the location of the cursor.
+If the customizable variable @code{calc-context-sensitive-enter} is
+non-@code{nil} (@pxref{Customizing Calc}), these commands will become
+context sensitive. For example, instead of duplicating the top of the stack,
+@key{RET} will copy the element at the cursor to the top of the
+stack. With a positive numeric prefix, a copy of the element at the
+cursor and the appropriate number of preceding elements will be placed
+at the top of the stack. A negative prefix will still duplicate the
+specified element of the stack regardless of the cursor position.
+Similarly, @key{DEL} will remove the corresponding elements from the
+stack.
+
@kindex @key{TAB}
@pindex calc-roll-down
To exchange the top two elements of the stack, press @key{TAB}
which is not a Lisp list.
Large integers are stored as lists of the form @samp{(bigpos @var{d0}
-@var{d1} @var{d2} @dots{})} for positive integers 1000000 or more, or
-@samp{(bigneg @var{d0} @var{d1} @var{d2} @dots{})} for negative integers
-@mathit{-1000000} or less. Each @var{d} is a base-1000 ``digit,'' a Lisp integer
-from 0 to 999. The least significant digit is @var{d0}; the last digit,
+@var{d1} @var{d2} @dots{})} for sufficiently large positive integers
+(where ``sufficiently large'' depends on the machine), or
+@samp{(bigneg @var{d0} @var{d1} @var{d2} @dots{})} for negative
+integers. Each @var{d} is a base-@expr{10^n} ``digit'' (where again,
+@expr{n} depends on the machine), a Lisp integer from 0 to
+99@dots{}9. The least significant digit is @var{d0}; the last digit,
@var{dn}, which is always nonzero, is the most significant digit. For
-example, the integer @mathit{-12345678} is stored as @samp{(bigneg 678 345 12)}.
+example, the integer @mathit{-12345678} might be stored as
+@samp{(bigneg 678 345 12)}.
The distinction between small and large integers is entirely hidden from
the user. In @code{defmath} definitions, the Lisp predicate @code{integerp}
is @code{nil}.
@end defvar
+@defvar calc-context-sensitive-enter
+The commands @code{calc-enter} and @code{calc-pop} will typically
+duplicate the top of the stack. If
+@code{calc-context-sensitive-enter} is non-@code{nil}, then the
+@code{calc-enter} will copy the element at the cursor to the
+top of the stack and @code{calc-pop} will delete the element at the
+cursor. The default value of @code{calc-context-sensitive-enter} is
+@code{nil}.
+@end defvar
+
@defvar calc-undo-length
The variable @code{calc-undo-length} determines the number of undo
steps that Calc will keep track of when @code{calc-quit} is called.