private static @NotNull DfType isNaN(DfaCallArguments arguments, DfaMemoryState state, DfType nan) {
    DfType type = state.getDfType(arguments.myArguments[0]);
    return type.isSuperType(nan) ? type.equals(FLOAT_NAN) || type.equals(DOUBLE_NAN) ? TRUE : BOOLEAN : FALSE;
  }
private static @NotNull DfType isNaN(DfaCallArguments arguments, DfaMemoryState state, DfType nan)