ModeShape requires to use 'JOIN' instead of ',' when joining 2 tables

Issuing either query:

SELECT c.jcr_name FROM relational_table AS t, relational_column AS c WHERE JCR.JCR_ISCHILDNODE(c.jcr_path, t.jcr_path)

SELECT c.jcr_name FROM relational_table AS t JOIN relational_column AS c ON JCR.JCR_ISCHILDNODE(c.jcr_path,t.jcr_path)

produces the following exception:

Caused by: javax.jcr.query.InvalidQueryException: The JCR-SQL2 query "SELECT g_1."jcr:name", g_1."jcr:path" FROM "relational:table" AS g_0, "relational:column" AS g_1 WHERE ISCHILDNODE(g_1, g_0)" is not well-formed: Unexpected token ',' at line 1, column 66
at org.modeshape.jcr.JcrQueryManager.createQuery(JcrQueryManager.java:146)
at org.modeshape.jcr.JcrQueryManager.createQuery(JcrQueryManager.java:101)
at org.modeshape.jdbc.delegate.LocalRepositoryDelegate.execute(LocalRepositoryDelegate.java:139)
at org.modeshape.jdbc.JcrStatement.execute(JcrStatement.java:429)
... 15 more

And after a discussion with Randall, it seems ModeShape needs JOIN in the syntax, and not ',' to join the tables.