1007.lean:8:77-8:82: warning: declaration uses 'sorry'
1007.lean:9:72-9:77: warning: declaration uses 'sorry'
1007.lean:11:49-11:54: warning: declaration uses 'sorry'
1007.lean:17:30-17:35: warning: declaration uses 'sorry'
1007.lean:34:91-34:96: warning: declaration uses 'sorry'
1007.lean:35:30-35:35: warning: declaration uses 'sorry'
1007.lean:39:79-39:84: warning: declaration uses 'sorry'
1007.lean:40:35-40:40: warning: declaration uses 'sorry'
1007.lean:57:64-57:78: error: failed to synthesize
  IsLin fun x => sum fun i => norm x
(deterministic) timeout at 'typeclass', maximum number of heartbeats (20000) has been reached (use 'set_option synthInstance.maxHeartbeats <num>' to set the limit)