+ if i != -1:
+ return i
+ i = find_token(document.header, '\\use_bibtopic', 0)
+ if i == -1:
+ i = find_token(document.header, '\\cite_engine', 0)
+ if i == -1:
+ i = find_token(document.header, '\\use_mathdots', 0)
+ if i == -1:
+ i = find_token(document.header, '\\use_mhchem', 0)
+ if i == -1:
+ i = find_token(document.header, '\\use_esint', 0)
+ if i == -1:
+ i = find_token(document.header, '\\use_amsmath', 0)