Text buttons
============

   This kind of button allows you to insert digits, functions, etc. in
the expression. You can also do this using the Amiga keyboard, but
these buttons offer a convenient shortcut. Note that the expression
parser is not case sensitive, so you can type it in upper or lower
case. The text buttons are:

`log'
     if pressed alone produces the string `Log(', indicating the
     *logarithm* function (using base 10); if you press `Inv' before,
     you obtain the string `10^'.

`ln'
     if pressed alone produces the string `Ln(', indicating the *natural
     logarithm* function (using base e); if you press `Inv' before, you
     obtain the string `e^'.

`x2'
     if pressed alone produces the string `^2', indicating the square;
     if you press `Inv' before, you obtain the string `Sqrt('
     indicating the *squareroot* function.

`mod'
     when pressed, produces the string `Mod(' indicating the function
     *modulus*. `Mod(A,B)' is the remainder of the division A/B.

`sin'
     if pressed alone produces the string `Sin(' indicating the
     trigonometric function *sine*; if you press `Inv' before, you
     obtain the string `ArcSin(', indicating the *arcsine* function;
     note that result of these functions depends on the measuring
     system unit chosen. If you press `Hyp' before, you obtain the
     string `Sh(' or `ArcSh(', indicating the *hyperbolic sine* and its
     inverse function;

`cos'
     if pressed alone produces the string `Cos(', indicating the
     trigonometric function *cosine*; if you press `Inv' before, you
     obtain the string `ArcCos(' indicating the *arccosine* function;
     note that result of these functions depends on the measuring
     system unit chosen. If you press `Hyp' before, you obtain the
     string `Ch(' or `ArcCh(' indicating the *hyperbolic cosine* and
     its inverse function;

`tan'
     if pressed alone produces the string `Tan(', indicating the
     trigonometric function *tangent*; if you press `Inv' before, you
     obtain the string `ArcTan(' indicating the *arctangent* function;
     note that result of these functions depends on the measuring
     system unit chosen. If you press `Hyp' before, you obtain the
     string `Th(' or `ArcTh(' indicating the *hyperbolic tangent* and
     its inverse function;

`and'
     when pressed, produces the string `and' indicating the binary
     *and* operator. The operand are implicitely forced to 32-bit
     integers, before performing the operation.

`or'
     when pressed, produces the string `or' indicating the binary *or*
     operator. The operand are implicitely forced to 32-bit integers,
     before performing the operation.

`not'
     when pressed, produces the string `not' indicating the binary
     *not* pre-operator. The operand are implicitely forced to 32-bit
     integers, before performing the operation.

`xor'
     when pressed, produces the string `xor' indicating the binary
     *xor* operator. The operand are implicitely forced to 32-bit
     integers, before performing the operation.

`fct'
     when pressed, produces the string `Fact(' indicating the
     *factorial* function.

`rnd'
     when pressed, produces the string `Rnd(' indicating a
     *one-parameter* function, for the generation of a pseudo-random
     number. If x is the value of the parameter, the number will be
     generated in the range `[0,X]' if X`>0', in the range `[X,0]'
     otherwise.

`( & )'
     these buttons produce the corresponding character.

`pi'
     this button produces the string `Pi' indicating the symbolic
     constant `PI', whose internal value is `3.14159265358979323846'

`e'
     this button produces the string `e' indicating the symbolic
     constant `e' (Napier's constant), whose internal value is
     `2.718281828459045'.

`0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F'
     when pressed,these buttons produce the corresponding character,
     indicating a digit. Obviously, when you compose an expression, the
     number interpretation depend on the numeric base you have set.
     Note that all these keys will always work, even if in some bases
     they should not be used.

`Exp'
     this button produces the `E' character, that you have to use to
     type a number in exponential form. This character is not different
     from the e indicating the Napier's constant, or from the `E' digit
     in hexadecimal base; its interpretation depend on the context in
     which it is found.

`,'
     this button produces the corresponding character, needed to
     separate the arguments of a function. Only the `Mod(A,B)' function
     has more than one argument, so you may feel that using keyboard is
     sufficient, however this button has been included to preserve the
     ability to use the calculator only by mouse.

`+,-,*,/,^'
     these buttons produce the corresponding character, indicating the
     *sum*, *difference, product, ratio* and *power* operators. Note
     that the minus sign can also be used as a preoperator to modify
     the sign of an operator.

`v,w,x,y,z'
     these buttons produce the corresponding character, indicating one
     of the five `ARcalc' variables. If, during the expression
     evaluation, `ARcalc' finds one of this variables, it use its
     current value. To learn how to assign a value to a variable, see
     the description of the `sto' button.