boolean (Exprent expr, Integer index) { if (expr.type == Exprent.EXPRENT_ASSIGNMENT) { Exprent left = ((AssignmentExprent)expr).getLeft(); if (left.type == Exprent.EXPRENT_VAR) { VarExprent var = (VarExprent)left; if (var.getIndex() == index) { var.setDefinition(true); return true; } } } return false; }