Let [inline-graphic not available: see fulltext] and [inline-graphic not available: see fulltext] be entire functions of order less than 1 with [inline-graphic not available: see fulltext] and [inline-graphic not available: see fulltext] transcendental. We prove that every solution [inline-graphic not available: see fulltext] of the equation [inline-graphic not available: see fulltext], [inline-graphic not available: see fulltext], [inline-graphic not available: see fulltext][inline-graphic not available: see fulltext] being has zeros with infinite exponent of convergence.