# Matlab simplify boolean expression

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ket on 27 May 2012
Commented: Ibrahim Elewah on 26 Jun 2022
I want to simplify a boolean algebra expression. I have taken this example from matlab online help but it does not work:
simplify((a and b) or (a and (not b)), logic)
Any suggestion?
I am using matlab R2012a (7.14.0.739)

Geoff on 27 May 2012
The expression:
(A && B) || (A && ~B)
Is logically equivalent to:
A
The reason is that both terms require A to be true, and the whole expression evaluates to true regardless of whether B is true or false. If you drew up a truth table for this, it'd be immediately obvious.
[EDIT] Hadn't clicked that the poster was talking about the symbolic math toolbox.
syms a,b;
simplify( (a & b) | (a & ~b) )
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Geoff on 28 May 2012
Cheers.. I should stop answering outside my area of experience. =)
Oleg Komarov on 28 May 2012
But that's how you learn new things!

Alexander on 29 May 2012
You have copied a MuPAD command. Did you use it inside a MuPAD Notebook? If not, type this at the MATLAB command prompt:
This will open a MuPAD Notebook. There, paste the input near the bracket (red text should appear) and press enter:
[ simplify((a and b) or (a and (not b)), logic)
a
If you don't want to open a MuPAD notebook, try this in MATLAB:
evalin(symengine, 'simplify((a and b) or (a and (not b)), logic)')
Though if you prefer to stay in MATLAB, you should take what Geoff suggests:
syms a b;
simplify((a & b) | (a & ~b))
(For some reason it did not work for me with the comma between a and b).
ket on 29 May 2012
Ibrahim Elewah on 26 Jun 2022
Thank You @Alexander

ket on 27 May 2012
Ok, but how do use matlab to simplify a boolean expression? Also, it there a method where I can see the intermediate steps?
Geoff on 28 May 2012
I don't have the symbolic math toolbox.. Does this work?
syms a,b;
simplify( (a & b) | (a & ~b) )