An `@`

used for an escape character; rules currently in force
are as follows.

`@`

`n`-
The evaluated result of
`n`-th input command `@@`

- The evaluated result of the last command
`@i`

- The unit of imaginary number, square root of -1.
`@pi`

- The number pi, the ratio of a circumference of the circle and its diameter.
`@e`

- Napier's number, the base of natural logarithm.
`@`

- A generator of GF(2^m), a finite field of characteristic 2, over GF(2). It is a root of an irreducible univariate polynomial over GF(2) which is set as the defining polynomial of GF(2^m).
`@>, @<, @>=, @<=, @==, @&&, @||`

- Fist order logical operators. They are used in quantifier elimination.

[0] fctr(x^10-1); [[1,1],[x-1,1],[x+1,1],[x^4+x^3+x^2+x+1,1],[x^4-x^3+x^2-x+1,1]] [1] @@[3]; [x^4+x^3+x^2+x+1,1] [2] eval(sin(@pi/2)); 1.000000000000000000000000000000000000000000000000000000000 [3] eval(log(@e),20); 0.99999999999999999999999999998 [4] @0[4][0]; x^4-x^3+x^2-x+1 [5] (1+@i)^5; (-4-4*@i) [6] eval(exp(@pi*@i)); -1.0000000000000000000000000000 [7] (@+1)^9; (@^9+@^8+@+1)

As you can see in the above example,
results of toplevel computation can be referred to
by `@`

convention.
This is convenient for users, while it sometimes imposes a heavy
burden to the garbage collector.
It may happen that GC time will rapidly increase after computing
a very large expression at the toplevel.
In such cases `delete_history()`

(see section `delete_history`

) takes effect.

Go to the first, previous, next, last section, table of contents.