Answer architecture round 1: exempt only a calc operand from the read-once refusal, run the name passes from one list, read every operand's leaves, show a name operand in a README example, and plan a path through a name as an operand

name_test.go

@@ -204,6 +204,10 @@ func TestNameErrors(t *testing.T) {
 			"a binding names nothing"},
 		{"read once whole", map[string]string{"word": `["a","b"]`, "card": `{"format":"{/word as w}{x}","x":"{w}"}`},
 			`write {/word}`},
+		{"read once whole, as a transform's operand", map[string]string{"word": `["a","b"]`, "card": `"{/word as w}{uppercase(w)}"`},
+			`write /word where it is read`},
+		{"read once whole, as a calc's operand", map[string]string{"n": `["2","3"]`, "card": `"{/n as k}{calc(k * 2)}"`},
+			""},
 		{"rendered twice where a path reads it", map[string]string{"word": `{"format":"{w}-{w}","w":["a","b"]}`, "card": `"{/word as n}{n}|{n.w}"`},
 			`{n} renders field "w" twice`},
 		{"a binding in a cell", map[string]string{"word": `["a","b"]`, "t.json": `{"format":"{k}","rows":"t.tsv","key":"k"}`, "t.tsv": "k\tc\nx\t{/word as w}{w}{w}\ny\tz\n"},