insert oddity

[annakh71]

Consider any empty keyed table t; insert of another empty tablewith the appropriate structure (e.g., t itself) will fail with a typeerrorbut upsert will succeed. I am a bit nonplussed by this behaviour;what is the rationale?q)t:([a:0#0n];b:0#`)q)upsert[t;t];q)insert[t;t];'type