Prolog: Reading input with spaces causes an error

this is my program

tran('father','otosan').
tran('father','chichiwe').
tran('mother','okasan').
tran('mother','hahawe').
tran('hi','ohayo').
tran('good night','oyasemi').
tran('good bye','sayonara').
tran('do your best','gambaru').
tran('please','onegai').
tran('sorr开发者_Go百科y','gomen').
tran('thank you','aregatto').
tran('cute','kawaii').
eng:- nl,write('enter a word in english: '),read(X),jap(X).
jap(X):- tran(X,Y),write('the word in japanese is '),write(Y),nl,fail.
jap(Z).
:-eng.

I got an error in the words with spaces

how can I solve this problem?

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It appears that when inputting words with spaces, you need to surround them with single quotes:

?- ['trans.pl'].
% trans.pl compiled 0.00 sec, 5,432 bytes
true.

?- eng.

enter a word in english: hi.
the word in japanese is ohayo
false.

?- eng.

enter a word in english: 'good bye'.
the word in japanese is sayonara
false.

The reason this is happening is that when you enter hi, Prolog is unifying it to jap(hi). which resolves to ohayo. When you enter good bye, Prolog unifies it to jap(good bye), which will give you an error (Operator Expected). This is why you need to quote your input as 'good bye'. Prolog will then unify it to jap('good bye'), which gives you what you want.