Unique rules when forming that grammar are highlighted like this.
Example sentences follow these rules too!
Joining and Nesting Markers:
Verb[た/る] - means that dictionary form and ta form are accepted.
Verb[causative[て]] - means て form of the causative form of the verb.
(A) に難くない is a formal phrase that means taking situation/context into account it is “not hard” to imagine/guess or understand something. It is only used with a limited number of expressions, among which the most common is 想像. Less common than that are 予想、察する、理解 and 推測.