ja: read nPk permutations with the school phrase, in display order

Rules/Languages/ja/SharedRules/general.yaml

@@ -105,14 +105,16 @@
   - t: "同じ式が評価されるマイナス"      # phrase(this result is 'minus the same expression evaluated at' an earlier point)
   - x: "*[2]"
 
-- name: permutation
-  # Not a default because the order of the args is reversed
+- name: permutation   # audit-ignore
+  # en reverses the args ("k permutations of n"); Japanese reads nPk in display
+  # order with the standard school phrase: 5P2 = "5 個から 2 個取る順列"
   tag: pochhammer
   match: "count(*)=2 and contains(@data-intent-property, ':infix:')"
   replace:
-  - x: "*[2]"
-  - t: "順列の"      # phrase(the solution  involves several 'permutations of' values)
   - x: "*[1]"
+  - T: "個から"      # phrase(the solution  involves several 'permutations of' values)
+  - x: "*[2]"
+  - T: "個取る順列"
 
 - name: intervals
   tag: [open-interval, open-closed-interval, closed-interval, closed-open-interval]

tests/Languages/ja/ja.rs

@@ -629,3 +629,15 @@ fn divides_and_similar() -> Result<()> {
     }
     return Ok(());
 }
+
+/// nPk permutation notation is read with the standard Japanese school phrase
+/// and in display order: (superscript 5) P (subscript 2) is
+/// "5 個から 2 個取る順列" ("permutations taking 2 out of 5").
+/// en reverses the arguments ("2 permutations of 5"); Japanese does not need to.
+#[test]
+fn permutation_p_notation() -> Result<()> {
+    let expr = "<math><msubsup><mi>P</mi><mn>2</mn><mn>5</mn></msubsup></math>";
+    test("ja", "ClearSpeak", expr, "5 個から 2 個取る順列")?;
+    test("ja", "SimpleSpeak", expr, "5 個から 2 個取る順列")?;
+    return Ok(());
+}