"sin"       // sine
"cos"       // cosine
"tg"        // tangent
"sinh"      // sine hyperbolic
"cosh"      // cosine hyperbolic
"tgh"       // tangent hyperbolic
"arcsin"    // arcus sine
"arccos"    // arcus cosine
"arctg"     // arcus tangent
"arcsinh"   // arcus sine hyperbolic
"arccosh"   // arcus cosine hyperbolic
"arctgh"    // arcus tangent hyperbolic
"sqrt"      // square root
"exp"       // exponential
"log"       // logaritm natural
"log10"     // logaritm decadic
"log2"      // logaritm binary
"abs"       // absolute value
"sgn"       // signum
"fix"       // fixed-point part
"frac"      // floating-point part
"rnd"       // random number
"comb"      // combination
"perm"      // permutation
// special functions:
"quit"      // quit application
"tree"      // print internal notation of arguments
"print"     // print arguments (print strings, process&print expressions)
"time"      // seconds elapsed since 1970-01-02
"plot"      // draw graph, args are: expr, symbol, from, to[, cols, rows, pretty]
"symbols"   // list defined symbols and their values
"diff"      // symbolic differentiaion (derivation), args are: expr, symbol[, grade, xvalue]