@addlike lesson text 1
$CENTER
*THE DISCOVERY
   In the writings of ancient Egyptians, there are stories about a separate universe, a vast expanse of space existing within another dimension.  The stories also make references to carriages capable of speeds "faster than light from the sun."
@addlike lesson text 2






   Scientists speculate that space voyagers from a distant galaxy visited the earth thousands of years ago.  The tales of their travels are known as:
@addlike lesson text 3
$CENTER
   The physical laws of our universe do not apply in the X-zone.  The X-zone has no planets or moons.  Nothing exists there except spherical entities named orbs.  These are unique forms of matter and energy that behave in mysterious ways.
@addlike lesson text 4
$ABOVE CENTER
   The orbs are similar in size, but there are two kinds, positive and negative.  They are as different as night and day.
   Positive orbs glow with blue light.  ~Press 1 to see a positive orb.~  
   Negative orbs appear to be hollow.  A faint yellow ring makes them visible.  ~Type -1 to observe a negative orb.~
@addlike lesson 1
   For millions of years, orbs were separated by great distances. Gradually, some drifted close enough to each other for gravity to pull them together.
   As in arithmetic, positive one and positive one equal positive two.  (Except for zero, which is neither positive nor negative, a number with no sign is positive.)  ~Press Enter to add the orbs.~
@addlike lesson 2
   When negative orbs join with others of their kind, the result is also a pair or group.  Negative two plus negative four equals negative six.  ~Press Enter.~
@addlike practice intro
   ~For each of the following eight problems, add the orbs, type your answer, and press Enter.~ For 10 points, find the sum of the orbs on your first attempt.  Score 5 points for a correct answer on your second try. Good luck!
@addunlike lesson 1
$CENTER
*POSITIVE MEETS NEGATIVE
   Scientists are not sure what really happens when positive and negative orbs enter the same gravitational field.  (A field is formed when orbs are close enough to each other for gravity to affect their motion.)
   Whereas positive orbs occupy space, negative orbs create voids in space.  A negative orb is similar to a hole in the sand.  When it is filled, it disappears.
   ~Press the Page Down key (or click the mouse on the arrow) to see positive energy fill a negative void.~
@addunlike lesson 2
   When groups of orbs with opposite energies meet, the group with more orbs will have at least one of its kind remain in spherical form.  ~Press Enter to add the orbs.~
@addunlike practice
   This is the first of ten gravitational fields where positive and negative orbs will meet. ~Type the sum of the orbs, and press Enter.~  Score a maximum of 10 points in each field.
@challenge text
$CENTER
*X-ZONE CHALLENGE I
   In each of the following fields, the orbs will be moving.  To score points, you must ~type the sum and press Enter~ before the groups meet.  In the licensed software, this game has 20 randomly selected problems and 3 levels of difficulty.  This shareware program will end the game after 5 problems at level 1.
@addlike transpage pass
$ERASE BACKGROUND
   [FirstName], you have successfully completed the first part of your  assignment in the X-zone.  That was excellent work!
@addlike transpage fail
   It takes some time to get used to using a negative sign.  A little more practice is all you need [FirstName].  Good work so far!
@addunlike transpage pass
$ERASE BACKGROUND
   You have done very well, [FirstName].  Acquiring the skill to add integers is an admirable feat that qualifies you to proceed to the first X-zone Challenge.
@addunlike transpage fail
   [FirstName], you will need to prepare well for the challenge ahead.  Keep up the good work!
@challenge transpage
   Addition of integers is a difficult skill to master.  You have done well.  Now you have several options from which to choose.  You may wish to improve your score or take a balloon ride on earth.
@end