S.sm (20 KiB) downloaded 80 time(s).

Re-defining units is actually calling for trouble. In the given case, re-defining °C does not switch off the conversion mechanism, which is triggered when displaying results in non-absolute temperature units (which does not happen when you use the non-unit custom constant °C). I would not call this a bug, because re-defining units is nothing which I would expect to be supported and consistently handled. One might call it a bug, that re-definition of units is possible at all (just as with the imaginary unit, which unfortunately is re-defined if a value is assigned to the variable i).

Hi. The result of solve is thinking that the variables can be complex. To obtain a more concrete result, you can use isolate. And this allows the more comfortable use of the units, without the need to "sterilize" them (Pompelmo dixit)

S.sm (15 KiB) downloaded 80 time(s).



Best regards.
Alvaro.

Note: For me, the convention that uppercase letters represent intensive variables and lowercase letters extensive variables is very practical. Thus, temperature and pressure always appear in capital letters, and volume, enthalpy, entropy and energy can be upper or lower case. The units, if intensive, will say whether they are volumetric, mass or molar quantities.

I'm completely lazy - I'm solving the simplest equation on the computer, not in my head!

16-12-T-Gamma.sm (10 KiB) downloaded 80 time(s).

I remember one undeserved math insult at school. The teacher asked me what the sine of 45 degrees is equal to. I didn't try to memorize the table of trigonometric functions, but tried to calculate the required values in my head. So, I think, the angle of an isosceles right triangle is 45 degrees. Its legs are 1, then the hypotenuse, according to the Pythagorean theorem, is equal to the root of two. And tangent is the ratio of the opposite side to the hypotenuse. My answer was one divided by the root of two! The teacher said: “I’ll put this 1 (very bad school ball in USSR) in the journal for you!” The sine of 45 degrees is equal to the root of two divided by two!
This resentment repeated itself in my adult years. I wrote a textbook on thermodynamics, or rather, on using packages with units of measurement to solve thermodynamics problems. It contained the entry T := 18°C. This textbook caught the eye of a venerable scientist. He leafed through it and said: “The author is an illiterate person in thermodynamics! If temperature on the Celsius scale is entered into the calculation, it is entered into the variable t. The absolute temperature in Kelvin is written into the variable T!”