+You can use the interactive loop (run the interpreter with no args)
+to check how statements are parsed.
Notice that programs develop through usage of
first_persons and second_persons, so for example
Remember me. # 0 in stack, -1 stays as value
Recall your ancestry! # empty stack, 0 as value
+Notice that everything afte 'recall' is ignored up to the sentence terminator.
Please see the test suite and the examples/* files for