Eh. So split it up. x1 strictly > x2 impliex x1 - x2 > 0
x1 > 0 and x1 < pi implies sin(x1) > 0
the sum of two positive quantities is positive.
x = sym('x', [1 2], 'real')
assume(0.0001>x>0 & x(1)>x(2))
y1 = x(1) + x(2)
y2 = sin(x(1))
isAlways(y1 > 0)
isAlways(y2 > 0)
syms y3 y4 %y3 is the positive quantity y1, y4 is the positive quantity sin(x(1))
assume(y3>0 & y4>0)
isAlways(y3+y4 > 0)
