having seen 是完成时态,这个词组通常用于表达 “因” “果”关系,
比如
Having seen the way you expertly negotiate the Beijing traffic,I think I'll leave the driving to you from now on.
看到你如此熟练地应对在北京驾车的挑战,我想我会从今以后把驾车的任务完全交给你.
the way you expertly negotiate the Beijing traffic 是 “因”
I'll leave the driving to you from now on 是 “果”.
希望帮到了你.