▁the ▁red ▁block " ▁and ▁then ▁" take ▁the ▁cone ▁off "; ▁" the ▁cone " ▁would ▁be ▁taken ▁to ▁mean ▁the ▁green ▁cone ▁one ▁had ▁just ▁talked ▁about . ▁S HR DL U ▁could ▁search ▁back ▁further ▁through ▁the ▁interactions ▁to ▁find ▁the ▁proper ▁context ▁in ▁most ▁cases ▁when ▁additional ▁ad ject ives ▁were ▁supplied . ▁One ▁could ▁also ▁ask ▁questions ▁about ▁the ▁history , ▁for ▁instance ▁one ▁could ▁ask ▁" did ▁you ▁pick ▁up ▁anything ▁before ▁the ▁cone ?" ▁ ▁A ▁side ▁effect ▁of ▁this ▁memory , ▁and ▁the ▁original ▁rules ▁S HR DL U ▁was ▁supplied ▁with , ▁is ▁that ▁the ▁program ▁could ▁answer ▁questions ▁about ▁what ▁was ▁possible ▁in ▁the ▁world ▁and ▁what ▁was ▁not . ▁For ▁instance , ▁S HR DL U ▁would ▁dedu ce ▁that ▁blocks ▁could ▁be ▁stack ed ▁by ▁looking ▁for ▁examples , ▁but ▁would ▁realize ▁that ▁tri angles ▁couldn ' t ▁be ▁stack ed , ▁after ▁having ▁tried ▁it . ▁The ▁" world " ▁contained ▁basic ▁physics ▁to ▁make ▁blocks ▁fall ▁over , ▁independent ▁of ▁the ▁language ▁parser . ▁ ▁Finally , ▁S HR DL U ▁could ▁also ▁remember ▁names ▁given ▁to ▁objects , ▁or ▁arrang ements ▁of ▁them . ▁For ▁instance ▁one ▁could ▁say ▁" a ▁ste e ple ▁is ▁a ▁small ▁triangle ▁on ▁top ▁of ▁a ▁tall ▁rectangle "; ▁S HR DL U ▁could ▁then ▁answer ▁questions ▁about ▁ste e ples ▁in ▁the ▁blocks ▁world , ▁and ▁build ▁new ▁ones . ▁ ▁Ex cer pt ▁ ▁Here ▁is ▁a ▁famous ▁demonstr ation