Check if B is composed of substrings of A of length n Given two strings \$ A \$  and \$ B \$ and a positive integer \$ n \$, determine whether \$ B \$ is composed entirely of (possibly overlapping) strict substrings of \$ A \$ of a length of at least \$ n \$.
Test cases
n  A               B               Output
-----------------------------------------
2  abcdefg         bcabcdebcdef    True
2  abcdefg         cdabfg          True
4  abracadabra     abrabrabrabra   True
1  abcdefg         ddbfeg          True
2  ab              abab            True
2  bb              bbbbb           True
5  abcdefghijklmn  defghabcdefghi  True
2  abcdefg         hijklmn         False
3  abcdefg         bcabcdebcdef    False
2  abcdefg         ddabfg          False
2  ab              aba             False
2  abcdefg         a               False
4  abracadabra     brabrabrabra    False
6  abcdefghijklmn  defghabcdefghi  False

Rules

You may assume that both \$ A \$ and \$ B \$ are non-empty; \$ n \ge 1 \$; and \$ A \$ has a length of at least \$ n \$
You may choose to operate on arrays with elements of any data type or set of values, rather than strings, as long as there are at least 8 distinct values for that element type
You can output using truthy or falsey values, or any two other disjoint sets of values, to indicate a true or false result
You may use any sensible I/O format
Standard loopholes are forbidden
This is code-golf, so the shortest code in bytes wins
Excel, 114 bytes
A nice low bar to start with.
=LET(x,SEQUENCE(LEN(C1)),t,TRANSPOSE(x),AND(MMULT((x&lt;t+A1)*(x&gt;=t),IFERROR(FIND(MID(C1&amp;REPT(&quot; &quot;,A1),x,A1),B1),0))))