Advice: Greek letters, upper and lower case
Except in the case of Pi , Zeta and Chi , a Greek letter name with its first character in uppercase (e.g. Delta ) is printed (in typeset output) as the corresponding Greek capital letter. A Greek letter name in lowercase (e.g. alpha ) is printed as the Greek lowercase letter. Pi and Zeta are used for the constant and the function, which are printed in lowercase. Chi , on the other hand, has nothing to do with Greek: its name stands for "hyperbolic cosine integral". You can use PI , ZETA and CHI to obtain these three uppercase Greek letters.
> Alpha, Beta, Gamma, Delta;
> alpha, beta, gamma, delta;
> Pi, PI, Zeta,ZETA, Chi, CHI;
See also: Pi , Zeta, Chi , Greek letters and other symbols in plots
Maple Advisor Database R. Israel, 1997