c

spec.md

@@ -358,14 +358,18 @@ def add = a -> b -> a + b
 - `func(arg1, arg2)`: function application. requires at least one argument. partial function applications are allowed too
 - `func(_, arg)`: bind some args from function, return funciton taking in the args with `_`, or the non-specified ones
 - `expr :: type`: down-cast type
-- `recExpr and otherRecExpr`: "sum" fields together of both record expressions.
-  type checking: phi-unify `recExpr` with `otherRecExpr`, and require that both are non-nominal record types
+- `recExpr and otherRecExpr`:
+  if both types are record types, or tagged record types:
+  - "sum" fields together of both record expressions.
+    type checking: phi-unify `recExpr` with `otherRecExpr`, and require that both are non-nominal record types
+  - else: identical to `\`a and b\`(a, b)`
 - `if cond then a else b`
 - `{field1: val1, field2: val2}` field construction
 - `match expr with <match cases>`: [pattern matching](##pattern-matching)
 - `'Tag expr`
 - `a = b` the [equality operator](##equality-operator)
 - `-a`: identical to `\`-a\`(a)` name: "negate"
+- `a or b`: identical to `\`a or b\`(a, b)` name: "or"
 - `a ^ b`: identical to `\`a^b\`(a, b)` name: "exponent"
 - `a + b`: identical to `\`a+b\`(a, b)` name: "sum"
 - `a - b`: identical to `\`a-b\`(a, b)` name: "difference"