"It is agreed that both parties to this agreement will review this Framework Agreement at the end of 2018."
That wording was vague about the exact timing of the review of the arrangement that keeps the Government in power.
But a political reality is now about to crystallise, as the future of the Government is set to be decided.
The Taoiseach wanted to get this process started in late August, and penned a letter crammed with ideas to Fianna Fáil.
Then Micheál Martin insisted this work could only begin after the Budget.
The call was described as pleasant and a structure to allow for an examination of the deal will now be put in place.
It's not clear yet though when the tough talking will begin.
But Micheál Martin indicated already that the serious work may not commence for a fortnight given the focus on the key EU summit on Brexit next week.
Indeed it is the topic that may have the greatest bearing on the outcome of any talks between Leo Varadkar and Micheál Martin.
Perhaps not unexpectedly, on the day of a budget that modestly benefited most, Leinster House was filled with rumours about a general election taking place before year's end.
There's even a date being mentioned - it's December 7th.
However, given the time it could take to get clarity on Brexit, that uncertainty may well prove to be a binding force that keeps this often precarious-looking administration in place for a while longer yet.
There's much talking to be done to make that happen though.
The Taoiseach had been looking forward to Micheál Martin's call and had already outlined what could be achieved in a new agreement running to 2020.
And although the Budget talks ran fairly smoothly, these negotiations may be a little more fraught.
Indeed there were some tetchy exchanges following revelations about what was discussed at Micheál Martin and Leo Varadkar's previous meeting in Killarney last July.
Micheál Martin then even branded the Taoiseach's actions in the aftermath of that meeting as immature.
Now the two must begin talking at length if this Government is going to mature a little more.