Universal spacetime permission;
1x + 1x = 2x is an allowable mathematical function in spacetime and allows for regular formation of bonding patterns and "creation" of matter via chemistry.
And another permission; 1x + 2x = 3x
Universal spacetime restriction;
1x + 1x = 3x is not an allowable mathematical function in spacetime and does not allow for the regular formation of bonding patterns in the "creation" of matter.
We hear about parallel universes where different mathematics might be functional. It is entirely possible that in another universe matter has different values. However, I doubt very much that the mathematical functions would be different. I cannot conceive of an "accounting system" which is more accurate or versatile than the mathematics of this universe, which man is fortunate to have recognized and codified for practical use.
Most organisms have the ability to tell (calculate) the difference between "more" and "less", "farther" and "closer", "faster" and "slower".
The latter mathematics often used by predatory animals, via instinctive cognition and use of "triangulation".
Humans have been able to codify the instinctive mathematical calculations into a formal language, which has evolved into a complete and accurate description of known natural universal values and functions (except at Planck scale). Not a small accomplishment.
IMO, human mathematics are the perfect translation of the known inherently mathematical natural potentials of this universe. The abstract language of universal dynamical chronological functions, such as CDT (causal dynamical triangulation), or any conceptually "mathematically allowable" chronology in pattern formation.