Some of the most massive, active commercial AI systems in the world, such as Google 
Search, are in fact hybrids that mix symbol-manipulation operations with deep 
learning. While Google Search is hardly what we have in mind for robust artificial 
intelligence, it is a highly effective AI-powered information retrieval system that works 
at enormous volume with a high degree of accuracy. Its designers have optimized it 
extensively in a highly data-driven way and are currently (according to multiple 
sources) achieving best results by mixing techniques from classic, symbol-manipulating 
AI (e.g., tools for representing and querying Google Knowledge Graph, which 
represents knowledge using classic symbolic graph structures that) with tools from the 
neural network community (e.g., BERT and RankBrain).  Google does an enormous 
empirical experimentation to see what works well on a vast scale, and the fact they still
The Next Decade in AI-