When changing the observation conditions used in special relativity, we get a new model called inverse relativity, we mentioned this in the second paper ( Modified Lorentz transformations and Minkowski space Splits in Inverse Relativity ) and third paper ( Positive and Negative Energy in Inverse Relativity ), where we find the relativistic variables in the classic observation conditions or in the special relativity becomes inverse variables in the new observation conditions, such as the length in the direction of motion in the new observation conditions remains constant instead of contraction, this means that the contraction of length expands until it reaches its original value, the time also contracts until it becomes super time instead of dilating with increasing the speed of the reference frame, the simultaneity between two events separated by a distance relative to an observer in the new observation conditions, the two events remain simultaneous relative to the other observer instead of non-simultaneity, the mass and energy in the new observation conditions are decreasing rather than increasing with the speed of the reference frame, the relativistic momentum in the new observation conditions remains constant, this means that the increase in relativistic momentum decreases until it reaches its original value, We conclude from all this that the relativistic variables in special relativity appear inverted in the new model, This is why the model is called the inverse theory of relativity