phosphate(out) + H(+)(out) => phosphate(in) + H(+)(in)
phosphate(out) + h(+)(out) => phosphate(in) + h(+)(in)
phosphate(out) + H(+)(out) => phosphate(in) + H(+)(in)
phosphate(out) + h(+)(out) => phosphate(in) + h(+)(in)