Why vpasolve fails with piecewise functions?

I am trying to solve an equation by vpasolve function but I have observed that the function fails when piecewise function are involved in the computation. Here below the instructions and the solutions.

Please can you help me?

Best regards,

Federica Gioia

%Symbolic variables

syms malphau nalphau alphaf

%Symbolic piecewise functios

malphau=piecewise(0<alphaf<1, 11/10 - alphaf/10)

nalphau=piecewise(0<alphaf<1, -((111*alphaf)/10 - 2537/50)/(12*alphaf + 28))

% Solutions using VAPSOLVE with or without initial point

Pyutot=vpasolve(malphau==nalphau, alphaf)

Pyutot =

Empty sym: 0-by-1

Pyutot=vpasolve(malphau==nalphau, alphaf,0)

Pyutot =

Empty sym: 0-by-1

Pyutot=vpasolve(malphau==nalphau, alphaf,0.5)

Pyutot =

Empty sym: 0-by-1

%So it seams that there are no solutions even if I change the initial point.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% Symbolic functions (WITHOUT using piecewise functions)

malphau=11/10 - alphaf/10

nalphau=-((111*alphaf)/10 - 2537/50)/(12*alphaf + 28)

% Solutions using VAPSOLVE

Pyutot=vpasolve(malphau==nalphau, alphaf)

Pyutot =

0.98117409934254853809751846778507

16.935492567324118128569148198882

% There are two solutions!

[Walter Roberson]

the second is invalid as it is outside 0 to 1 in a range the piecewise would calculate as nan.

0 is outside the strict inequalities

[federica gioia]

Thank you for your answer.

Surely the second solution is out of range but what about the first one?