Charles Bradley made a similar suggestion with a conditional promise in advance. He suggested.

Charles Bradley提出了类似的建议，不过他指出还要获得一个有条件的承诺。

youdao

A promise conditional on a performance by the promisor is a promise of alternative performances within 77 unless occurrence of the condition is also promised.

以诺言人的某一履行为条件的诺言，为第77条规定的选择履行，条件的出现也是诺言内容的除外。

youdao

My promise to help you is conditional upon your good behavior.

我答应帮助你，要以你的品行好为条件。

youdao

And the promise was phrased in the conditional.

NEWYORKER: Great Experiment

Reconciliation of the Taliban is conditional and it would require any Taliban soldier or official to renounce the use of violence, promise allegiance to the Afghan constitution, disavow al Qaeda.

WHITEHOUSE: Press Briefing

The Guardian reported that News Corp. withdrew its promise to spin off Sky News as a separately listed publicly-traded company, a conditional part of their previously negotiated takeover deal.

FORBES: Murdoch's News Corp. Expands Buyback With BSkyB Takeover In Limbo