Changes CoefficientsX to CoefficientsY

[RickBrice]

CoefficientsX are limited to CoefficientsX[0] and CoefficientsX[1].

The correct coefficient for y = a*x^2 is CoefficientsY[3]

[SergejMuhic]

I have to disagree, but also with the original. My proposal:
y = ax^2 + by + c

is CoefficientsX[3]=a, CoefficientsX[2]=b, CoefficientsX[1]=c and CoeffiecientsY[2]=1.

[aothms]

Thanks for spotting this, I agree with Sergej but, oh dear, the "semantic definition" on the entity does not help us much.

Also looping in @civilx64 and @evandroAlfieri for the validation service because there are some "informal propositions" hidden in the text here (which are indeed wrong, X/Y should be swapped)

• The size of the attribute CoefficientsY (sic) is restricted to 3 [. The quadratic term is on position 3]
• [In general,] the CoefficientsX (sic) size would be restricted to 2 and values specified as [0, 1].

I would format these in the text as a bullet list so that they stand out a bit more.

Actions:

• Adapt example to Sergej's (and format using latex)
• Swap text X <-> Y
• Reformat text
• Provide some entity and attribute definition on the entity page
• Implement rule in VS