log(x,2)−log(2,y)*log(x,y) < 4(log(2,x) − log(2,y)) https://www.wolframalpha.com/input?i=log%28x%2C2%29%E2%88%92log%282%2Cy%29*log%28x%2Cy%29+%3C+4%28log%282%2Cx%29+%E2%88%92+log%282%2Cy%29%29&lang=ja
log(x,2)−log(2,y)*log(x,y) < 4(log(2,x) − log(2,y))
https://www.wolframalpha.com/input?i=log%28x%2C2%29%E2%88%92log%282%2Cy%29*log%28x%2Cy%29+%3C+4%28log%282%2Cx%29+%E2%88%92+log%282%2Cy%29%29&lang=ja