@mmcdara Very nice.

@Carl Love I had noticed that too. Is there a way to see the steps simplify takes? Maybe it only uses each euqation once. Years ago when I doing simplification or substitutions into a polynomail along the lines of reducing a 5th order to 4th order I found I had to repetatively use algsubs in a loop to get the order from 5 down to 4. Those equations where huge so one couldnt really follow what was happening. So i am presuming this could be a slightly similar phenomea. 

@Carl Love Very nice. I have now  re-found this data in the help. I had read it  several years ago but at that time did not have an immediate application. Voted up.

Looking at the new application site. I am not a fan of the whole tile turning bule when mousing over it. That is quite distracting and hides what it is. The tiles could be made smaller so more are visible too.

OK. Use the green up arrow button and post a copy of your work sheet. Then people can see what you are doing.

@acer  Ahh,  I wasn't at my pc when I posted the answer. My mistake.

@Anthrazit  did you try this op(1,b)<op(1,a) or is( op(1,b)<op(1,a)). That works for me in Maple2021.1 using the Units-Standard package. Yes it's probable a bug.

@Anthrazit This gives a True answer.  This post should really be converted to a question.

if is(op(1, b) < op(1, a)) then
    "True";
else
    "False";
end if

Edit:-
I purposely kept in "is" because it forces evaluation.

if 1 < sqrt(2) then
    "True";
else
    "False";
end if;
Error, cannot determine if this expression is true or false: 1 < 2^(1/2)
if is(1 < sqrt(2)) then
    "True";
else
    "False";
end if;

You can see the problem  by looking at op(A), it has two parts when A is non  zero i.e. value,unit but only one part when A is zero i.e. value.

Try if is(a<b) then "True" else ""False" end if

@acer  Just out of interest. Are there other situations outside of trig. where solve misses solutions? I mean towards relatively simple type equations like what is presented above. I realise that might be hard to define.

@acer  Thank you. Nice to read the history and orign of such things.

@tomleslie Am using this version. Thank you.

@vv     @tomleslie explained the cause of my problem well in the first reply. I have since converted the formula.

@tomleslie  Thank you. I understand now. Had never read the details on || or cat. Also checking over replies to my series of questions this year some of the answers have become clearer. The m's formula is extendible. So I just could build it around the size of the list L which I would probably call M. So for example  (1 + m2 + 2*m3 + 3*m4 + 4*m5 + 5*m6 + 6*m7)!  would become (1+add(i * M[i], i=1..nops(M)))! , assuming my typing is correct here.

@acer I should have taken more care. Basicially I was looking for 

 5*c^3+ 21*c^2*d + 28*c*d^2 + 12*d^3 

as the 3rd degree form. I was able to get things working properly overall. 

I have combined you answer with  the answer to a previous question I asked  https://www.mapleprimes.com/questions/232082-Is-It-Possible-To-Addsum-By-Mapping#comment278942 

Download 25_Polynomial_General_Expansion.mw