TILDE// The ~ operator is a special form, as it is not a postfix operator. When the interpreter encounters a ~, it pushes the next token on the stack as is regardless of whether it is a defined name.
SLASH// /
STAR// *
FALSE// false
TRUE// true
PI// 3.14159
E// 2.718
EOF// end of file
POP// Pops and discards the top item on the stack. The literal meaning is discard.
DUP// Duplicates the top object on the stack.
EXCH// Inverts the order of the top two objects on the stack.
CLEAR// Empties the stack.
REMEMBER// Puts a flag (like PostScript’s mark) on the stack. The internal representation of the flag is not available to the programmer.
FORGET// Clears the stack down to the flag and pops the flag. If there is no flag present, the stack is emptied completely.
DUMP// Prints the contents of the operand stack to STDOUT without changing them.
NAME// Associates obj with id and places it in the system lookup space. Conventionally used to associate new operator names with procedure objects.
SET// Reassigns the value of a value already in the system lookup space. Used primarily for variable assignments.
