# The Greek Alphabet

Greek letters are transliterated using their English names. I.e.

[alpha,beta,gamma,delta,epsilon,zeta,eta,theta,iota,kappa,lambda,mu,nu,xi,omicron,pi,rho,sigma,tau,upsilon,phi,chi,psi,omega]


Upper case Greek letters have an upper-case English first letter. I.e.

[Alpha,Beta,Gamma,Delta,Epsilon,Zeta,Eta,Theta,Iota,Kappa,Lambda,Mu,Nu,Xi,Omicron,Pi,Rho,Sigma,Tau,Upsilon,Phi,Chi,Psi,Omega]


Many of the Greek letters already have a meaning in Maxima.

• beta: The beta function is defined as $\gamma(a) \gamma(b)/\gamma(a+b)$.
• gamma: The gamma function.
• delta: This is the Dirac Delta function (only defined in Laplace).
• zeta: This is the Riemann zeta function.
• lambda: Defines and returns a lambda expression, i.e. an unnamed function.
• psi: The derivative of 'log (gamma ())' of order '+1', which has a strange syntax psi[n](x). It is also defined in the tensor package.

Note that by default, psi requires arguments and any attempt to use this variable name without arguments will result in an error. For this reason we delete this function in STACK, and psi becomes an unnamed variable.

The following are given a specific value by STACK.

• pi is defined to be the numeric constant which is the ratio of the diameter to the circumference of a circle. In Maxima this is normally %pi, but STACK also defines the letter pi to have this value.
• In Maxima the numeric constant which represents the so-called golden mean, $(1 + \sqrt{5})/2$ is %phi.

## "Undefine" Maxima defaults

It is currently not possible to "undefine" function names and return them to variables.