int sub 0 sup 1 f left ( x right ) ^ \[u2146] x = sum from {i = 0} to inf x sub i = prod from {i = 0} to inf x sub i = \[u2210] from {i = 0} to inf x sub i = \[u222E] sub 0 sup 1 f left ( x right ) ^ \[u2146] x = \[u222C] sub 0 sup 1 f left ( x right ) ^ \[u2146] x = \[u222D] sub 0 sup 1 f left ( x right ) ^ \[u2146] x