term-rewriting rule in Kit

gistfile1.txt

% cat src/test.kit
rules AddOne {
    (ADD_ONE(${x: Int})) => x + 1;
}
using rules AddOne;

function main() {
    var foo = ADD_ONE(42_i);
}
% 
% kitc test
[2018-10-25 03:11:49.492853] ===> parsing and building module graph
[2018-10-25 03:11:49.508318] ===> processing C includes
[2018-10-25 03:11:49.666179] ===> resolving module types
[2018-10-25 03:11:49.691016] ===> typing module content
----------------------------------------
Error: src/test.kit:7: Unknown identifier: ADD_ONE

  @src/test.kit:7:15-21
       7        var foo = ADD_ONE(42_i);
                          ^^^^^^^

[2018-10-25 03:11:49.709233] ===> total time: 0.216120481s
[2018-10-25 03:11:49.709540] ERR: compilation failed (1 errors)
%