%e represents the base of the natural logarithm, also known as Euler’s
number.  The numeric value of %e is the double-precision floating-point
value 2.718281828459045d0.  (See A&S eqn 4.1.16, A&S 4.1.17.)
%i represents the imaginary unit, 
\(\sqrt{-1}\).
false represents the Boolean constant of the same name.
Maxima implements false by the value NIL in Lisp.
The Euler-Mascheroni constant, 0.5772156649015329.... It is defined by (A&S eqn 6.1.3 and DLMF 5.2.ii) $$ \gamma = \lim_{n \rightarrow \infty} \left(\sum_{k=1}^n {1\over k} - \log n\right) $$
ind represents a bounded, indefinite result.
See also limit.
Example:
(%i1) limit (sin(1/x), x, 0); (%o1) ind
inf represents real positive infinity.
infinity represents complex infinity.
The least negative floating-point number in Maxima.  That is, the
negative floating-point number closest to 0.  It is approximately
-4.94065e-324, when
denormal numbers
are supported.  Otherwise it is the same as
least_negative_normalized_float.
The least negative normalized floating-point number in Maxima. That is, the negative normalized floating-point number closest to 0. It is approximately -2.22507e-308.
The least positive floating-point number in Maxima.  That is, the
positive floating-point number closest to 0.  It is approximately
4.94065e-324, when
denormal numbers
are supported.  Otherwise it is the same as
least_positive_normalized_float.
The least positive normalized floating-point number in Maxima. That is, the positive normalized floating-point number closest to 0. It is approximately 2.22507e-308.
minf represents real minus (i.e., negative) infinity.
The most negative floating-point number in Maxima. It is approximately -1.79769e+308.
The most positive floating-point number in Maxima. It is approximately 1.797693e+308.
%phi represents the so-called golden mean, 
\((1+\sqrt{5})/2\).
The numeric value of %phi is the double-precision floating-point value
1.618033988749895d0.
fibtophi expresses Fibonacci numbers fib(n) in terms of
%phi.
By default, Maxima does not know the algebraic properties of %phi.
After evaluating tellrat(%phi^2 - %phi - 1) and algebraic: true,
ratsimp can simplify some expressions containing %phi.
Examples:
fibtophi expresses Fibonacci numbers fib(n) in terms of %phi.
(%i1) fibtophi (fib (n));
                           n             n
                       %phi  - (1 - %phi)
(%o1)                  -------------------
                           2 %phi - 1
(%i2) fib (n-1) + fib (n) - fib (n+1);
(%o2)          - fib(n + 1) + fib(n) + fib(n - 1)
(%i3) fibtophi (%);
            n + 1             n + 1       n             n
        %phi      - (1 - %phi)        %phi  - (1 - %phi)
(%o3) - --------------------------- + -------------------
                2 %phi - 1                2 %phi - 1
                                          n - 1             n - 1
                                      %phi      - (1 - %phi)
                                    + ---------------------------
                                              2 %phi - 1
(%i4) ratsimp (%);
(%o4)                           0
By default, Maxima does not know the algebraic properties of %phi.
After evaluating tellrat (%phi^2 - %phi - 1) and algebraic: true,
ratsimp can simplify some expressions containing %phi.
(%i1) e : expand ((%phi^2 - %phi - 1) * (A + 1));
                 2                      2
(%o1)        %phi  A - %phi A - A + %phi  - %phi - 1
(%i2) ratsimp (e);
                  2                     2
(%o2)        (%phi  - %phi - 1) A + %phi  - %phi - 1
(%i3) tellrat (%phi^2 - %phi - 1);
                            2
(%o3)                  [%phi  - %phi - 1]
(%i4) algebraic : true;
(%o4)                         true
(%i5) ratsimp (e);
(%o5)                           0
%pi represents the ratio of the perimeter of a circle to its diameter.
The numeric value of %pi is the double-precision floating-point value
3.141592653589793d0.
true represents the Boolean constant of the same name.
Maxima implements true by the value T in Lisp.
und represents an undefined result.
See also limit.
Example:
(%i1) limit (x*sin(x), x, inf); (%o1) und
zeroa represents an infinitesimal above zero.  zeroa can be used
in expressions.  limit simplifies expressions which contain
infinitesimals.
Example:
limit simplifies expressions which contain infinitesimals:
(%i1) limit(zeroa); (%o1) 0 (%i2) limit(x+zeroa); (%o2) x
zerob represents an infinitesimal below zero.  zerob can be used
in expressions.  limit simplifies expressions which contain
infinitesimals.